[R4R] Change gas & related fields to unsigned integer type

[alexanderbez]

Update gas consumption and fields to utilize uint64 over int64. I believe the corresponding changes should also be made in TM for abci.ResponseDeliverTx, abci.ResponseCheckTx, and BlockSize.MaxGas so we don't have to cast.

closes: #2815

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• Wrote tests

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[codecov]

Codecov Report

Merging #2839 into develop will decrease coverage by 0.17%.
The diff coverage is 80%.

@@             Coverage Diff             @@
##           develop    #2839      +/-   ##
===========================================
- Coverage       57%   56.83%   -0.18%     
===========================================
  Files          131      131              
  Lines         8581     8575       -6     
===========================================
- Hits          4892     4874      -18     
- Misses        3359     3370      +11     
- Partials       330      331       +1

[ValarDragon]

Consume gas should check for overflow

[alexanderbez]

Yes @ValarDragon -- the PR is not complete yet.

[alexanderbez]

Failing due to a regression in #2781.

[cwgoes]

Tested ACK

This has been addressed by subsequent commits.