feat: Adds class-name and data- props to error boundaries

[pan-kot]

Description

This change allows passing custom class names or data-* attributes to the fallback. It is consistent with how findErrorBoundary() test-util only finds the component when in fallback state.

The change is needed to pass a particular data-attribute to the default fallback message, which is used to alter the runtime behaviour of alerts (coming from the awsuiPlugins.alert runtime API):

// Wrong: this affects both the alert in EB fallback but also all alerts in the content
<div data-runtime-behaviour="off">
  <ErrorBoundary ... />
</div>

// Works (with this change)
<ErrorBoundary ... data-runtime-behaviour="off" />

How has this been tested?

• Unit tests

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 97.18%. Comparing base (ea2b35b) to head (20bb8cf).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4221   +/-   ##
=======================================
  Coverage   97.18%   97.18%           
=======================================
  Files         883      883           
  Lines       25866    25867    +1     
  Branches     9344     9344           
=======================================
+ Hits        25137    25138    +1     
  Misses        723      723           
  Partials        6        6           

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