Enable category-based narrowing and reset to default on search clear

[shinshin86]

This PR modifies the search behavior in the settings dialog to allow category-based narrowing of results. When a user initiates a search, the activeCategory is set to null, displaying all matching results across categories. Users can then click an enabled category to further refine those matches.

Additional Fix: Text Changes During Search

Previously, certain labels would change unexpectedly when search results were displayed (e.g., "Edit Token Weight" became "EditAttention," as shown in the attached images). This PR resolves that issue, ensuring text remains consistent regardless of whether a search is active.

before:

after:

Please review these changes at your convenience, and feel free to share any questions or feedback.
Thank you for your time and support!

Demo video:

filter_setting_result.mp4

[huchenlei]

Nice feature! I basically rewrite the impl for it to be more maintainable. The rule of thumb here is to avoid introducing extra ground states (Vue ref). In the rewrited version, the no extra ref is introduced. (searchResult ref is changed to restore search result setting id).

The extra state on SettingTreeNode to check whether the category is disabled is also simplified. (No extra floating state to maintain)