add xevidence system contract

[codecov-commenter]

Codecov Report

Merging #448 (f56ac81) into master (11347bd) will decrease coverage by 0.02%. The diff coverage is 33.33%.

:exclamation: Your organization needs to install the Codecov GitHub app to enable full functionality.

@@            Coverage Diff             @@
##           master     #448      +/-   ##
==========================================
- Coverage   43.93%   43.91%   -0.02%     
==========================================
  Files         149      149              
  Lines       13355    13358       +3     
==========================================
- Hits         5867     5866       -1     
  Misses       6307     6307              
- Partials     1181     1185       +4     

Files Changed	Coverage Δ
bcs/ledger/xledger/ledger/genesis.go	41.33% <ø> (ø)
kernel/engines/xuperos/chain.go	47.10% <33.33%> (-0.17%)	:arrow_down:

... and 4 files with indirect coverage changes

:mega: We’re building smart automated test selection to slash your CI/CD build times. Learn more

:loudspeaker: Have feedback on the report? Share it here.