Add text search to the Awesome report Tags dropdown

### What problem should this solve?

We use custom tags to associate automated test results with software requirements. A test may cover one or several requirements, and a complete CI report may contain hundreds or thousands of unique requirement tags.

A reviewer often starts with a specific requirement ID and needs to find every test result associated with it across multiple suites, platforms, and test types.

The current Tags dropdown shows the entire tag list without a search field. The reviewer must manually scroll through hundreds or thousands of requirement IDs to find the desired tag.

For example, a report may contain tags such as:

- `REQ-1234`
- `REQ-1235`
- `REQ-1236`

If a reviewer needs evidence for `REQ-1235`, locating it manually in a very large dropdown is impractical.

This affects workflows such as:

- Requirements traceability and compliance reviews
- Finding all results associated with one requirement
- Reports combining multiple platforms and test frameworks
- Tests associated with multiple requirements
- Automatically generated requirement tags that are not suitable for manual browsing

The existing tag filter works correctly after a tag is selected. The problem is finding the desired tag in a large dropdown.

### What would you like to happen?

Add a text search field at the top of the Tags dropdown.

The user should be able to enter a complete or partial requirement ID, and the dropdown should display only matching tags. For example, entering `REQ-1235` should immediately narrow the list to that requirement.

Expected behavior:

- Search is case-insensitive.
- Full and partial tag values are supported.
- Clearing the search restores the complete tag list.
- Existing selections remain selected when the search text changes.
- Multiple tags can still be selected.
- Tests associated with multiple requirements continue to appear for each matching tag.
- Existing URL persistence and shareable filtered links remain unchanged.
- Keyboard navigation works within the filtered results.

This would make the existing tag-filter feature practical for large requirements-based test reports without changing the underlying result format or filtering behavior.

### Alternatives considered

_No response_

### Additional context

_No response_

Start at the Awesome report's Tags dropdown and trace the existing tag-filter entry point. Review how selection, URL persistence, multi-select behavior, and keyboard navigation currently work; done means case-insensitive partial search narrows the list while preserving selections and shareable filtered links.

Written by the indexing model from the issue text.