Add batch verification

[id-ms]

Summary

Test Plan

[codecov-commenter]

Codecov Report

Merging #2578 (437ca32) into master (39be0c7) will increase coverage by 0.00%.
The diff coverage is 57.28%.

@@           Coverage Diff           @@
##           master    #2578   +/-   ##
=======================================
  Coverage   47.07%   47.07%           
=======================================
  Files         349      350    +1     
  Lines       55858    55925   +67     
=======================================
+ Hits        26294    26327   +33     
- Misses      26617    26646   +29     
- Partials     2947     2952    +5     

Impacted Files	Coverage Δ
crypto/multisig.go	45.34% <38.23%> (+9.15%)	⬆️
data/transactions/verify/txn.go	45.08% <43.90%> (-3.37%)	⬇️
crypto/batchverifier.go	100.00% <100.00%> (ø)
ledger/blockqueue.go	82.18% <0.00%> (-2.88%)	⬇️
network/wsPeer.go	72.14% <0.00%> (-2.23%)	⬇️
crypto/merkletrie/trie.go	66.42% <0.00%> (-2.19%)	⬇️
crypto/merkletrie/node.go	91.62% <0.00%> (-1.87%)	⬇️
ledger/acctupdates.go	62.05% <0.00%> (-0.26%)	⬇️
cmd/tealdbg/debugger.go	73.86% <0.00%> (+1.00%)	⬆️

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[tsachiherman]

looks good. two minor comments, but neither of them would be a blocker.

[tsachiherman]

Two small comments, but looks good otherwise!