fix: revert settings search results ordering

[rzhao271]

Fixes #197773

This PR partially reverts the ordering algorithm of the Settings editor search results so that keyword match results show up first. The table of contents order is still calculated and used in two cases:

1. When the search query only has filters, such as if the user is filtering down to a feature area with @feature, or an extension area with @ext.
2. As a last resort for two items that are determined to have the same relevancy.