fix: implement proper ResizeObserver mock for Cypress tests

[saloua-ch]

What does this PR do?

This PR replaces the current ResizeObserver error workaround with a proper mock implementation for Cypress tests. Fixes #10649

Why is this change needed?

The current solution in cypress/support/index.js simply ignores ResizeObserver errors using Cypress.on('uncaught:exception'). This isn't ideal because:

• It masks potential real issues
• It doesn't properly simulate ResizeObserver behavior
• It's not a maintainable long-term solution

How does this PR solve the problem?

• Implements a proper ResizeObserver mock that:
  • Correctly implements the ResizeObserver interface
  • Maintains a map of observed elements
  • Triggers callbacks appropriately
  • Provides proper cleanup methods
• Removes the old error-ignoring workaround
• Maintains all existing test functionality
• Properly organizes the mock file in the TypeScript-compatible directory structure

Related issues

Fixes #[your issue number] (replace with the actual issue number you created)

Testing

• [ ] All Cypress tests pass
• [ ] No ResizeObserver errors in test output
• [ ] Components still resize and behave as expected

Checklist

• [x] I have followed the project's coding style
• [x] I have added tests that prove my fix is effective
• [x] I have added necessary documentation (if applicable)
• [x] I have updated the changelog (if applicable)

[djhi]

Unfortunately the tests are failing

[djhi]

Any news on this one?