eth/tracers: refactor exporting js buffer

[s1na]

We had to do this workaround because it wasn't possible to export typed arrays from JS to []byte. This was added in dop251/goja@2352993.

As a sanity check I ran the call tracer benchmarks. Seems there's mostly no change in performance.

❯ benchstat before.bench after.bench         
name                                          old time/op    new time/op    delta
Tracers/create-8                                85.0µs ± 2%    88.7µs ± 2%  +4.33%  (p=0.008 n=5+5)
Tracers/deepCalls-8                              504µs ± 1%     524µs ± 2%  +3.99%  (p=0.008 n=5+5)
Tracers/delegatecall-8                          52.4µs ± 1%    53.0µs ± 1%    ~     (p=0.310 n=5+5)
Tracers/innerCreateOogOuterThrow-8               273µs ± 1%     272µs ± 2%    ~     (p=0.690 n=5+5)
Tracers/innerInstafail-8                        14.2µs ± 2%    14.3µs ± 1%    ~     (p=0.690 n=5+5)
Tracers/innerThrowOuterRevert-8                 45.1µs ± 1%    44.6µs ± 1%    ~     (p=0.151 n=5+5)
Tracers/oog-8                                   26.4µs ± 1%    26.2µs ± 1%    ~     (p=0.095 n=5+5)
Tracers/revert-8                                17.5µs ± 1%    17.4µs ± 2%    ~     (p=0.333 n=5+5)
Tracers/revertReason-8                          24.7µs ± 1%    24.7µs ± 1%    ~     (p=0.690 n=5+5)
Tracers/selfdestruct-8                          22.7µs ± 3%    22.6µs ± 2%    ~     (p=0.421 n=5+5)
Tracers/simple-8                                30.0µs ± 1%    30.1µs ± 0%    ~     (p=0.190 n=5+4)
Tracers/simpleOnlytop-8                         30.0µs ± 1%    30.3µs ± 1%    ~     (p=0.222 n=5+5)
Tracers/throw-8                                 20.1µs ± 1%    20.3µs ± 1%    ~     (p=0.095 n=5+5)
FlatCallTracer/bigSlow-8                        10.2ms ± 2%    10.2ms ± 1%    ~     (p=0.690 n=5+5)
FlatCallTracer/callcodePrecompiledFailHide-8     366µs ± 2%     366µs ± 2%    ~     (p=0.841 n=5+5)
FlatCallTracer/callcodePrecompiledOog-8          436µs ± 2%     432µs ± 1%    ~     (p=0.095 n=5+5)
FlatCallTracer/callcodePrecompiledThrow-8        403µs ± 1%     404µs ± 2%    ~     (p=1.000 n=5+5)
FlatCallTracer/create-8                          655µs ± 2%     658µs ± 2%    ~     (p=0.690 n=5+5)
FlatCallTracer/deepCalls-8                      4.03ms ± 1%    4.01ms ± 1%    ~     (p=0.310 n=5+5)
FlatCallTracer/delegatecall-8                    830µs ± 1%     823µs ± 1%    ~     (p=0.222 n=5+5)
FlatCallTracer/delegatecallParentValue-8         449µs ± 1%     450µs ± 1%    ~     (p=0.690 n=5+5)
FlatCallTracer/gas-8                             537µs ± 5%     519µs ± 3%    ~     (p=0.056 n=5+5)
FlatCallTracer/includePrecompiled-8             3.00ms ± 1%    2.99ms ± 1%    ~     (p=1.000 n=5+5)
FlatCallTracer/innerCreateOogOuterThrow-8       1.49ms ± 1%    1.51ms ± 2%    ~     (p=0.095 n=5+5)
FlatCallTracer/innerInstafail-8                  381µs ± 2%     389µs ± 5%    ~     (p=0.310 n=5+5)
FlatCallTracer/innerPrecompiledWrongGas-8       1.53ms ± 1%    1.54ms ± 1%    ~     (p=0.111 n=5+4)
FlatCallTracer/innerThrowOuterRevert-8           948µs ± 0%     964µs ± 2%    ~     (p=0.057 n=4+4)
FlatCallTracer/nestedCreate-8                    611µs ± 3%     609µs ± 2%    ~     (p=0.841 n=5+5)
FlatCallTracer/nestedCreate2ActionGas-8          437µs ± 8%     414µs ± 1%    ~     (p=0.222 n=5+5)
FlatCallTracer/nestedCreateActionGas-8           442µs ± 4%     419µs ± 2%  -5.08%  (p=0.016 n=4+5)
FlatCallTracer/nestedCreateInerror-8             424µs ± 5%     414µs ± 4%    ~     (p=0.556 n=4+5)
FlatCallTracer/nestedPointerIssue-8             3.53ms ± 5%    3.38ms ± 1%  -4.47%  (p=0.008 n=5+5)
FlatCallTracer/oog-8                             569µs ± 6%     550µs ± 2%    ~     (p=0.095 n=5+5)
FlatCallTracer/optionConvertParityErrors-8       573µs ± 3%     550µs ± 1%  -4.11%  (p=0.008 n=5+5)
FlatCallTracer/resultOutput-8                    646µs ± 8%     619µs ± 1%  -4.25%  (p=0.016 n=5+5)
FlatCallTracer/revert-8                          460µs ± 4%     454µs ± 2%    ~     (p=0.690 n=5+5)
FlatCallTracer/revertReason-8                    530µs ± 2%     524µs ± 2%    ~     (p=0.310 n=5+5)
FlatCallTracer/selfdestruct-8                    405µs ± 1%     407µs ± 2%    ~     (p=0.548 n=5+5)
FlatCallTracer/simple-8                          598µs ± 3%     594µs ± 1%    ~     (p=0.421 n=5+5)
FlatCallTracer/simpleOnlytop-8                   607µs ± 3%     607µs ± 2%    ~     (p=0.841 n=5+5)
FlatCallTracer/skipNoBalanceError-8              474µs ± 1%     473µs ± 1%    ~     (p=0.413 n=4+5)
FlatCallTracer/staticcallPrecompiled-8          1.11ms ± 1%    1.12ms ± 3%    ~     (p=0.690 n=5+5)
FlatCallTracer/suicide-8                         450µs ± 1%     458µs ± 2%    ~     (p=0.095 n=5+5)
FlatCallTracer/throw-8                           671µs ±13%     625µs ± 2%  -6.86%  (p=0.016 n=5+5)

name                                          old alloc/op   new alloc/op   delta
Tracers/create-8                                37.1kB ± 0%    37.1kB ± 0%  +0.10%  (p=0.032 n=5+5)
Tracers/deepCalls-8                              108kB ± 0%     108kB ± 0%    ~     (p=1.000 n=5+5)
Tracers/delegatecall-8                          13.4kB ± 0%    13.4kB ± 0%    ~     (p=0.571 n=5+5)
Tracers/innerCreateOogOuterThrow-8               128kB ± 0%     128kB ± 0%    ~     (p=1.000 n=5+5)
Tracers/innerInstafail-8                        5.02kB ± 0%    5.02kB ± 0%    ~     (p=0.286 n=5+5)
Tracers/innerThrowOuterRevert-8                 9.83kB ± 0%    9.83kB ± 0%    ~     (p=0.651 n=5+4)
Tracers/oog-8                                   6.39kB ± 0%    6.39kB ± 0%    ~     (p=0.333 n=5+4)
Tracers/revert-8                                6.58kB ± 0%    6.58kB ± 0%    ~     (p=0.468 n=5+5)
Tracers/revertReason-8                          8.69kB ± 0%    8.68kB ± 0%    ~     (p=0.690 n=5+5)
Tracers/selfdestruct-8                          7.72kB ± 0%    7.72kB ± 0%    ~     (p=0.651 n=5+4)
Tracers/simple-8                                8.17kB ± 0%    8.17kB ± 0%    ~     (p=0.079 n=4+5)
Tracers/simpleOnlytop-8                         8.17kB ± 0%    8.17kB ± 0%    ~     (p=0.190 n=5+5)
Tracers/throw-8                                 5.51kB ± 0%    5.51kB ± 0%    ~     (p=1.000 n=5+5)

name                                          old allocs/op  new allocs/op  delta
Tracers/create-8                                   101 ± 0%       101 ± 0%    ~     (all equal)
Tracers/deepCalls-8                                685 ± 0%       685 ± 0%    ~     (all equal)
Tracers/delegatecall-8                             126 ± 0%       126 ± 0%    ~     (all equal)
Tracers/innerCreateOogOuterThrow-8                 125 ± 0%       125 ± 0%    ~     (all equal)
Tracers/innerInstafail-8                          79.0 ± 0%      79.0 ± 0%    ~     (all equal)
Tracers/innerThrowOuterRevert-8                    111 ± 0%       111 ± 0%    ~     (all equal)
Tracers/oog-8                                     74.0 ± 0%      74.0 ± 0%    ~     (all equal)
Tracers/revert-8                                  75.0 ± 0%      75.0 ± 0%    ~     (all equal)
Tracers/revertReason-8                            96.0 ± 0%      96.0 ± 0%    ~     (all equal)
Tracers/selfdestruct-8                             112 ± 0%       112 ± 0%    ~     (all equal)
Tracers/simple-8                                   110 ± 0%       110 ± 0%    ~     (all equal)
Tracers/simpleOnlytop-8                            110 ± 0%       110 ± 0%    ~     (all equal)
Tracers/throw-8                                   70.0 ± 0%      70.0 ± 0%    ~     (all equal)