Properly handle gas in pointer precompile

[codchen]

Describe your changes and provide context

Previously gas is tracked in two places for a pointer precompile call: the gas meter in sdk.Context, and suppliedGas. This PR unifies them into sdk.Context so that we don't miscount or double-count gas usage.

Testing performed to validate your change

unit tests

[codecov]

Codecov Report

Attention: Patch coverage is 62.16216% with 14 lines in your changes missing coverage. Please review.

Project coverage is 60.73%. Comparing base (18c3e2d) to head (1370350).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
precompiles/pointer/pointer.go	33.33%	8 Missing ⚠️
x/evm/keeper/params.go	44.44%	4 Missing and 1 partial ⚠️
precompiles/common/precompiles.go	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1836      +/-   ##
==========================================
- Coverage   60.90%   60.73%   -0.18%     
==========================================
  Files         257      257              
  Lines       22690    22698       +8     
==========================================
- Hits        13820    13786      -34     
- Misses       7887     7932      +45     
+ Partials      983      980       -3     

Files with missing lines	Coverage Δ
x/evm/gov.go	38.46% <100.00%> (ø)
x/evm/keeper/pointer_upgrade.go	74.66% <100.00%> (+1.05%)	⬆️
x/evm/migrations/migrate_all_pointers.go	58.51% <100.00%> (ø)
precompiles/common/precompiles.go	51.23% <50.00%> (+0.93%)	⬆️
x/evm/keeper/params.go	70.96% <44.44%> (-10.86%)	⬇️
precompiles/pointer/pointer.go	36.00% <33.33%> (-0.07%)	⬇️

... and 2 files with indirect coverage changes