refactor(event-queue): improve event ordering

[glevco]

Motivation

Reliable integration events could be generated in a non-consistent order on different runs, caused by a for-loop on an unordered set in the consensus. Although this was worked-around, making the for-loop ordered improves predictability of said events and also simplifies tests.

Acceptance Criteria

• Sort the context.tx_affected for-loop in the consensus so its order is always the same
• Fix event tests
• Remove zip_chunkify() utils functions as it's not used anymore

Checklist

• If you are requesting a merge into master, confirm this code is production-ready and can be included in future releases as soon as it gets merged

[codecov]

Codecov Report

Merging #738 (2c3869d) into master (126017d) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #738      +/-   ##
==========================================
+ Coverage   84.55%   84.57%   +0.01%     
==========================================
  Files         252      252              
  Lines       21686    21688       +2     
  Branches     2936     2937       +1     
==========================================
+ Hits        18337    18342       +5     
+ Misses       2712     2710       -2     
+ Partials      637      636       -1     

Files Changed	Coverage Δ
hathor/consensus/consensus.py	97.89% <100.00%> (+0.04%)	⬆️

... and 3 files with indirect coverage changes