state: move pruneBlocks from consensus/state to state/execution

[JayT106]

state: move pruneBlocks function from consensus/state to state/execution

Closes #5414

[cmwaters]

LGTM, thanks for doing this @JayT106 👍

Looking at this, it seems that we've changed the behaviour of fast sync. Prior it seems like there was no pruning whilst fast syncing but it looks like now there will be. I believe that's fine 🤔

[codecov]

Codecov Report

Merging #6541 (22b4996) into master (32bc399) will decrease coverage by 0.03%.
The diff coverage is 61.36%.

@@            Coverage Diff             @@
##           master    #6541      +/-   ##
==========================================
- Coverage   61.08%   61.04%   -0.04%     
==========================================
  Files         295      295              
  Lines       27850    27848       -2     
==========================================
- Hits        17011    17000      -11     
- Misses       9124     9130       +6     
- Partials     1715     1718       +3     

Impacted Files	Coverage Δ
internal/blockchain/v2/processor_context.go	68.00% <0.00%> (ø)
internal/blockchain/v2/reactor.go	32.04% <ø> (ø)
internal/consensus/replay_file.go	0.00% <0.00%> (ø)
state/execution.go	66.19% <57.14%> (-0.85%)	⬇️
internal/blockchain/v0/reactor.go	65.21% <100.00%> (ø)
internal/consensus/replay.go	72.11% <100.00%> (ø)
internal/consensus/state.go	67.18% <100.00%> (+0.31%)	⬆️
internal/consensus/wal_generator.go	70.75% <100.00%> (ø)
node/node.go	51.77% <100.00%> (+0.07%)	⬆️
internal/consensus/peer_state.go	79.82% <0.00%> (-4.39%)	⬇️
... and 15 more