R4R: Check for gas overflow in tx validation

[alexanderbez]

closes #3068

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• Linked to github-issue with discussion and accepted design OR link to spec that describes this work.

• Wrote tests

• Updated relevant documentation (docs/)

• Added entries in PENDING.md with issue #

• rereviewed Files changed in the github PR explorer

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[ValarDragon]

This fixes the first issue! I still need to make an issue for the second case, will do after tm meeting.

[codecov]

Codecov Report

Merging #3070 into develop will increase coverage by <.01%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop    #3070      +/-   ##
===========================================
+ Coverage    52.16%   52.17%   +<.01%     
===========================================
  Files          136      136              
  Lines         9612     9614       +2     
===========================================
+ Hits          5014     5016       +2     
  Misses        4262     4262              
  Partials       336      336

[cwgoes]

Tested ACK