Templatize internal/matchers for all internaltest packages

[MrAlias]

Part of #3846

Follow up to #4424

The internaltest packages all import the otel/internal/matchers package. Use gotmpl to templatize this package and import a local copy for all internaltest copies.

Validated using the .golangci.yml file from #4426. It successfully runs with this change.

[codecov]

Codecov Report

Merging #4430 (cecfb49) into main (319cb3a) will decrease coverage by 2.4%.
The diff coverage is 4.0%.

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #4430     +/-   ##
=======================================
- Coverage   81.2%   78.8%   -2.4%     
=======================================
  Files        247     253      +6     
  Lines      20006   20645    +639     
=======================================
+ Hits       16258   16282     +24     
- Misses      3405    4014    +609     
- Partials     343     349      +6     

Files Changed	Coverage Δ
exporters/jaeger/internal/internaltest/harness.go	0.0% <ø> (ø)
exporters/jaeger/internal/matchers/expectation.go	0.0% <0.0%> (ø)
exporters/jaeger/internal/matchers/expecter.go	0.0% <0.0%> (ø)
exporters/zipkin/internal/internaltest/harness.go	0.0% <ø> (ø)
exporters/zipkin/internal/matchers/expectation.go	0.0% <0.0%> (ø)
exporters/zipkin/internal/matchers/expecter.go	0.0% <0.0%> (ø)
internal/matchers/expectation.go	0.0% <ø> (ø)
internal/matchers/expecter.go	0.0% <ø> (ø)
sdk/internal/internaltest/harness.go	100.0% <ø> (ø)
sdk/internal/matchers/expectation.go	8.3% <8.3%> (ø)
... and 1 more

... and 1 file with indirect coverage changes