refactor!: split gateway call functionality into separate contract

[milapsheth]

AXE-4553

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 77.77778% with 6 lines in your changes missing coverage. Please review.

Project coverage is 95.67%. Comparing base (97ca896) to head (ddeef36).

Files	Patch %	Lines
contracts/utils/GatewayCaller.sol	75.00%	2 Missing and 2 partials ⚠️
contracts/InterchainTokenService.sol	81.81%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #267      +/-   ##
==========================================
- Coverage   95.95%   95.67%   -0.29%     
==========================================
  Files          18       19       +1     
  Lines         594      601       +7     
  Branches      122      124       +2     
==========================================
+ Hits          570      575       +5     
  Misses         11       11              
- Partials       13       15       +2     

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