Remove time ledger tracker as not used

[algorandskiy]

Summary

Remove time ledger tracker as not used.
Bulletin tracker is also looks unused but might me useful while refactoring.

Test Plan

Use existing tests

[codecov-commenter]

Codecov Report

Merging #2937 (7469b6d) into master (e4842fc) will decrease coverage by 4.13%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2937      +/-   ##
==========================================
- Coverage   47.30%   43.17%   -4.14%     
==========================================
  Files         356      353       -3     
  Lines       57244    57206      -38     
==========================================
- Hits        27081    24700    -2381     
- Misses      27098    29512    +2414     
+ Partials     3065     2994      -71     

Impacted Files	Coverage Δ
ledger/ledger.go	62.65% <ø> (-3.06%)	⬇️
crypto/merklearray/worker.go	0.00% <0.00%> (-100.00%)	⬇️
crypto/compactcert/structs.go	0.00% <0.00%> (-100.00%)	⬇️
agreement/agreementtest/keyManager.go	0.00% <0.00%> (-100.00%)	⬇️
daemon/algod/api/server/lib/middlewares/auth.go	0.00% <0.00%> (-100.00%)	⬇️
agreement/agreementtest/simulate.go	0.00% <0.00%> (-87.68%)	⬇️
cmd/algofix/deadlock.go	3.12% <0.00%> (-84.38%)	⬇️
crypto/merklearray/partial.go	0.00% <0.00%> (-84.10%)	⬇️
ledger/onlineacct.go	17.64% <0.00%> (-82.36%)	⬇️
crypto/onetimesig.go	0.00% <0.00%> (-76.28%)	⬇️
... and 96 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update e4842fc...7469b6d. Read the comment docs.