Add coin and msg helpers

[shanev]

No description provided.

[codecov-commenter]

Codecov Report

Patch coverage: 39.21% and project coverage change: -13.01% ⚠️

Comparison is base (536724e) 90.56% compared to head (0512249) 77.56%.
Report is 139 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #17       +/-   ##
===========================================
- Coverage   90.56%   77.56%   -13.01%     
===========================================
  Files           4        7        +3     
  Lines         106      156       +50     
===========================================
+ Hits           96      121       +25     
- Misses         10       35       +25     

Files Changed	Coverage Δ
contracts/fair-burn/src/helpers.rs	100.00% <ø> (+37.50%)	⬆️
contracts/fair-burn/src/state.rs	88.88% <ø> (ø)
packages/sg-std/src/lib.rs	0.00% <0.00%> (ø)
contracts/fair-burn/src/contract.rs	95.12% <25.00%> (-3.62%)	⬇️
packages/sg-multi-test/src/multi.rs	40.00% <40.00%> (ø)
packages/sg-std/src/msg.rs	45.45% <45.45%> (ø)

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.