metrics: split alive check counter between early/dead

[cce]

Summary

This splits the "dead" txhandler counters between "early" and "dead" to track them separately.

Test Plan

Update existing counter tests.

[codecov]

Codecov Report

Merging #4898 (17f67ef) into master (fb95de1) will decrease coverage by 0.02%.
The diff coverage is 90.00%.

@@            Coverage Diff             @@
##           master    #4898      +/-   ##
==========================================
- Coverage   54.06%   54.04%   -0.03%     
==========================================
  Files         427      427              
  Lines       53520    53528       +8     
==========================================
- Hits        28935    28927       -8     
- Misses      22316    22329      +13     
- Partials     2269     2272       +3     

Impacted Files	Coverage Δ
data/transactions/error.go	50.00% <ø> (ø)
data/transactions/transaction.go	42.90% <0.00%> (-0.14%)	⬇️
data/pools/transactionPool.go	49.77% <100.00%> (+0.11%)	⬆️
data/txHandler.go	63.60% <100.00%> (+0.75%)	⬆️
ledger/tracker.go	72.15% <0.00%> (-5.91%)	⬇️
ledger/blockqueue.go	85.63% <0.00%> (-2.88%)	⬇️
catchup/peerSelector.go	97.38% <0.00%> (-2.62%)	⬇️
ledger/testing/randomAccounts.go	56.00% <0.00%> (-0.62%)	⬇️
ledger/acctupdates.go	68.63% <0.00%> (-0.37%)	⬇️
catchup/service.go	69.80% <0.00%> (-0.25%)	⬇️
... and 4 more

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