test: improve fungible module coverage

[skosito]

Description

Bumps fungible module coverage from 80 to 90%. Coverage was already improved before (#1742), but this improves it a bit more. This is also last issue in the epic #1739 so epic can also be closed when this is merged.

Closes: #1977

Type of change

Tests

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Include instructions and any relevant details so others can reproduce.

• Tested CCTX in localnet
• Tested in development environment
• Go unit tests
• Go integration tests
• Tested via GitHub Actions

Checklist:

• I have added unit tests that prove my fix feature works

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 65.11%. Comparing base (9eb55e7) to head (4213c41).

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1985      +/-   ##
===========================================
+ Coverage    63.91%   65.11%   +1.20%     
===========================================
  Files          236      236              
  Lines        13639    13610      -29     
===========================================
+ Hits          8717     8862     +145     
+ Misses        4505     4375     -130     
+ Partials       417      373      -44     

Files	Coverage Δ
x/fungible/keeper/evm.go	87.43% <100.00%> (+18.35%)	⬆️
x/fungible/keeper/evm_hooks.go	100.00% <100.00%> (+20.00%)	⬆️
x/fungible/keeper/gas_coin_and_pool.go	89.04% <ø> (+24.65%)	⬆️

... and 9 files with indirect coverage changes

[skosito]

@lumtis are params used for this module or is it same as crosschain and should be removed?

[kingpinXD]

lgtm , left a few minor comments

[lumtis]

👍