ledger: Remove redundant block header cache

[algonautshant]

This PR removes headerCache blockHeaderCache from Ledger struct.
All requests to BlockHdr function which were fulfilled by headerCache are now addressed by l.txTail.blockHeader, and fallback, when the txTail does not have the round, to l.blockQ.getBlockHdr.

All instances of BlockHdrCached are eliminated or replaced by BlockHdr.

Impact on the locks:

• The locking scheme had to change to make this possible. Mainly, l.trackerMu will no longer protect the txTail, instead, txTail mutex will be responsible for protecting the txTail actions.
• BlockHdrCached function will no longer lock l.trackerMu.
• trackerRegistry initialize will be guarded by the tr.mu lock.

Resolves: https://github.com/algorand/go-algorand-internal/issues/2147

#5566 will address the test failure since it is independent of this work.

[codecov]

Codecov Report

Merging #5540 (77c3b4c) into master (d82200a) will decrease coverage by 0.10%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #5540      +/-   ##
==========================================
- Coverage   55.06%   54.96%   -0.10%     
==========================================
  Files         465      463       -2     
  Lines       64584    64468     -116     
==========================================
- Hits        35561    35437     -124     
- Misses      26652    26659       +7     
- Partials     2371     2372       +1     

Files Changed	Coverage Δ
cmd/tealdbg/localLedger.go	66.84% <ø> (+0.71%)	⬆️
daemon/algod/api/server/v2/dryrun.go	72.70% <ø> (+0.39%)	⬆️
ledger/eval/applications.go	38.63% <ø> (+0.43%)	⬆️
ledger/eval/cow.go	77.57% <ø> (+0.92%)	⬆️
ledger/eval/eval.go	51.04% <ø> (+0.11%)	⬆️
ledger/evalindexer.go	51.04% <ø> (+1.04%)	⬆️
data/transactions/logic/eval.go	92.18% <100.00%> (+0.05%)	⬆️
ledger/acctupdates.go	70.73% <100.00%> (-0.07%)	⬇️
ledger/ledger.go	69.47% <100.00%> (-1.09%)	⬇️
ledger/tracker.go	74.74% <100.00%> (-1.22%)	⬇️
... and 1 more

... and 13 files with indirect coverage changes

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[algorandskiy]

please remove exceed locks from txtal.commitRound

[algorandskiy]

Looking forward for part 2 with BlockHdrCached removal

[iansuvak]

Read through the PR, and the changes seem as described but I am not personally comfortable enough with the system and existing locking picture to approve myself.

The couple of questions that I do have are minor

[jannotti]

I confirmed that the AVM has its own check before calling BlockHdr() so the change to return headers from DB is fine from that perspective.

I don't want to weigh in on the locking discussion, since I don't know it well. But if you want my input, ping me and I'll spend more time understanding it.

I'm really glad to see this cleanup!

[algorandskiy]

@algonautshant there are some linter and benchmark failures like

Raw Output:
  data/transactions/logic/assembler.go:1: : # github.com/algorand/go-algorand/data/transactions/logic [github.com/algorand/go-algorand/data/transactions/logic.test]
  Error: [Lint Errors] reported by reviewdog 🐶
  cannot use ep.Ledger (variable of type LedgerForLogic) as LedgerForSignature value in assignment: LedgerForLogic does not implement LedgerForSignature (missing method BlockHdr) (typecheck)

Please take a look, most likely some benchmark mock is missing BlockHdr method