performance: Update two transaction verification benchmarks

[cce]

Summary

• update BenchmarkTxHandlerProcessDecoded to use bigger blocks and also measure verify.TxnGroup
• update BenchmarkTxnRoots to also call paysetCommitSHA256

Test Plan

No impact to code besides benchmark test changes.

[codecov]

Codecov Report

Merging #4552 (a291da0) into master (c03e3d3) will increase coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #4552      +/-   ##
==========================================
+ Coverage   54.03%   54.05%   +0.02%     
==========================================
  Files         401      401              
  Lines       51542    51542              
==========================================
+ Hits        27849    27860      +11     
+ Misses      21359    21348      -11     
  Partials     2334     2334              

Impacted Files	Coverage Δ
ledger/roundlru.go	90.56% <0.00%> (-5.67%)	⬇️
ledger/blockqueue.go	87.35% <0.00%> (-1.15%)	⬇️
catchup/service.go	68.64% <0.00%> (-0.25%)	⬇️
ledger/catchpointtracker.go	62.89% <0.00%> (ø)
network/wsNetwork.go	64.91% <0.00%> (+0.09%)	⬆️
data/transactions/logic/assembler.go	85.75% <0.00%> (+0.14%)	⬆️
ledger/acctupdates.go	70.19% <0.00%> (+0.59%)	⬆️
ledger/tracker.go	74.89% <0.00%> (+0.85%)	⬆️
network/wsPeer.go	68.19% <0.00%> (+2.15%)	⬆️

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