A helper to provide a bytes interface for r/w on Python object.

[sighingnow]

I think the vineyard backend in mars will needs such tools.

And it will simply the distributed (python) job that works on vineyard and needs job-specific value migration.

[codecov]

Codecov Report

Merging #286 (3193bf1) into main (cf1fbf5) will decrease coverage by 1.30%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #286      +/-   ##
==========================================
- Coverage   75.97%   74.66%   -1.31%     
==========================================
  Files          60       61       +1     
  Lines        4998     5073      +75     
==========================================
- Hits         3797     3788       -9     
- Misses       1201     1285      +84     

Impacted Files	Coverage Δ
src/server/util/proc.h	75.00% <0.00%> (-15.00%)	⬇️
src/server/server/vineyard_server.cc	73.77% <0.00%> (-1.23%)	⬇️
src/server/memory/allocator.cc	94.11% <0.00%> (-0.89%)	⬇️
src/common/util/env.h	76.92% <0.00%> (-0.86%)	⬇️
src/server/async/socket_server.cc	73.94% <0.00%> (-0.53%)	⬇️
src/server/memory/jemalloc.cc
src/server/util/kubectl.cc	0.00% <0.00%> (ø)
src/server/util/kubectl.h	0.00% <0.00%> (ø)
src/server/util/spec_resolvers.cc	72.58% <0.00%> (+0.44%)	⬆️