chore: update test coverage for ibc client

[bishalbikram]

Improve test cases for ics-02 client

• updated existing test cases
• added new test cases to cover edge cases

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 70.54%. Comparing base (3767742) to head (25407cb).
Report is 1 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #843      +/-   ##
============================================
+ Coverage     70.25%   70.54%   +0.28%     
  Complexity      414      414              
============================================
  Files           155      155              
  Lines         14028    14028              
  Branches        292      292              
============================================
+ Hits           9856     9896      +40     
+ Misses         4022     3982      -40     
  Partials        150      150              

Flag	Coverage Δ
rust	68.71% <ø> (+0.33%)	⬆️

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see 2 files with indirect coverage changes