fix: Improve dynamic adjustment of prompt input height

[jperals]

Description

Update the input height not only on window resize, but also when the component itself changes width for whatever reason (for example, by expanding or collapsing drawers). Otherwise the prompt input height will become stale in these cases.

Issue: AWSUI-62050

How has this been tested?

• Integration tests
• Manually

Review checklist

The following items are to be evaluated by the author(s) and the reviewer(s).

Correctness

• Changes include appropriate documentation updates.
• Changes are backward-compatible if not indicated, see CONTRIBUTING.md.
• Changes do not include unsupported browser features, see CONTRIBUTING.md.
• Changes were manually tested for accessibility, see accessibility guidelines.

Security

• If the code handles URLs: all URLs are validated through the checkSafeUrl function.

Testing

• Changes are covered with new/existing unit tests?
• Changes are covered with new/existing integration tests?

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.45%. Comparing base (77cd842) to head (d53b96d).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4582      +/-   ##
==========================================
+ Coverage   97.43%   97.45%   +0.01%     
==========================================
  Files         941      942       +1     
  Lines       29692    29703      +11     
  Branches    10792    10792              
==========================================
+ Hits        28930    28946      +16     
- Misses        715      750      +35     
+ Partials       47        7      -40     

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