On tags page, allow restricting search to just tag names

[cellio]

meta:294005

The tags page for a category has a search box, which searches for the string in tag names or descriptions. This is a request for an option to search for names only -- you know you're looking for a tag name containing the string and don't want the hits from descriptions/wikis.

Adding another button alongside Usage, Hierarchy, Missing Excerpt doesn't feel right. The first two of those are for sorting/display. Possibly both "name only" and "missing excerpt" should be checkbox options with the search textbox, rather than sorting buttons that are visually aligned with the list/results.