feat: stmgr: call: use a buffered concurrent-access blockstore

[arajasek]

Related Issues

This is the correcter solution to #8351

Proposed Changes

Use a concurrent-access memory blockstore for the LegacyVM

Additional Info

Checklist

Before you mark the PR ready for review, please make sure that:

• All commits have a clear commit message.
• The PR title is in the form of of <PR type>: <area>: <change being made>
  • example: fix: mempool: Introduce a cache for valid signatures
  • PR type: fix, feat, INTERFACE BREAKING CHANGE, CONSENSUS BREAKING, build, chore, ci, docs,perf, refactor, revert, style, test
  • area: api, chain, state, vm, data transfer, market, mempool, message, block production, multisig, networking, paychan, proving, sealing, wallet, deps
• This PR has tests for new functionality or change in behaviour
• If new user-facing features are introduced, clear usage guidelines and / or documentation updates should be included in https://lotus.filecoin.io or Discussion Tutorials.
• CI is green

[codecov]

Codecov Report

Merging #8358 (3a121f9) into master (3a62c8b) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #8358      +/-   ##
==========================================
- Coverage   40.21%   40.20%   -0.02%     
==========================================
  Files         683      683              
  Lines       74478    74479       +1     
==========================================
- Hits        29955    29944      -11     
- Misses      39289    39296       +7     
- Partials     5234     5239       +5     

Impacted Files	Coverage Δ
chain/stmgr/call.go	69.18% <100.00%> (+0.16%)	⬆️
chain/events/observer.go	71.64% <0.00%> (-6.72%)	⬇️
chain/types/tipset_key.go	85.96% <0.00%> (-3.51%)	⬇️
chain/stmgr/searchwait.go	67.30% <0.00%> (-2.57%)	⬇️
chain/sub/incoming.go	45.25% <0.00%> (-2.45%)	⬇️
itests/kit/blockminer.go	69.56% <0.00%> (-1.09%)	⬇️
storage/wdpost_run.go	69.91% <0.00%> (-0.61%)	⬇️
extern/sector-storage/sched_worker.go	78.48% <0.00%> (-0.59%)	⬇️
chain/store/store.go	64.33% <0.00%> (-0.50%)	⬇️
chain/messagepool/selection.go	83.91% <0.00%> (-0.39%)	⬇️
... and 9 more