FI-2000: Improve frontend testing coverage

[AlyssaWang]

Summary

Adds test files for components previously missing tests

Testing Guidance

Run npm test, everything should pass.

Are there any other missing tests that aren't covered by current files?

[codecov]

Codecov Report

Patch coverage: 84.46% and project coverage change: -17.21 ⚠️

Comparison is base (87b7a5c) 94.47% compared to head (fe36f71) 77.27%.

Additional details and impacted files

@@             Coverage Diff             @@
##             main     #369       +/-   ##
===========================================
- Coverage   94.47%   77.27%   -17.21%     
===========================================
  Files         116      211       +95     
  Lines        3094    10318     +7224     
  Branches      381      953      +572     
===========================================
+ Hits         2923     7973     +5050     
- Misses        171     1786     +1615     
- Partials        0      559      +559     

Flag	Coverage Δ
backend	94.47% <ø> (ø)
frontend	69.90% <84.46%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
client/src/components/Footer/Footer.tsx	64.97% <ø> (ø)
client/src/components/_common/ActionModal.tsx	94.44% <ø> (ø)
...mponents/_common/SelectionPanel/SelectionPanel.tsx	84.34% <20.00%> (ø)
...nents/TestSuite/TestSuiteDetails/TestGroupCard.tsx	69.76% <50.00%> (ø)
...iteDetails/TestGroupListItem/TestGroupListItem.tsx	71.62% <50.00%> (ø)
...ite/TestSuiteDetails/TestListItem/TestListItem.tsx	69.54% <50.00%> (ø)
...nts/RequestDetailModal/__mocked_data__/mockData.ts	89.39% <55.55%> (ø)
.../TestSuiteDetails/TestListItem/InputOutputList.tsx	81.08% <66.66%> (ø)
...uite/TestSuiteDetails/TestListItem/MessageList.tsx	80.70% <66.66%> (ø)
...uite/TestSuiteDetails/TestListItem/RequestList.tsx	76.36% <66.66%> (ø)
... and 13 more

... and 72 files with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.