Rework admin searches and make them compatible with no-js again

[ocean90]

I'm working on #15355 and found some problems with the searches. I will use this ticket to add the patches, one patch for each problem which I have found.

A list with what it not working:

• Comments search doesn't work without JS fixed
• Users search doesn't work with and without JS fixed
• ​http://grab.by/7nC2 I like the idea with the new tab "Search Results (1)", but you will see it only in no-js version and only for themes and plugins search. We should add it for all searches, AJAX search and with no grey bgcolor to be consistent. Or we must respect the active tab like we did it on comments search, so if 'Sticky' tab is active search only through sticky posts and not all as it is yet. Consistent is the word here.

• Behaviour after a search without any results: With JS it's an empty table and with no-js we have the message "No xxx found."

Also, what's with the styling of "Search Results (1)"? I saw that the other day while giving a demo.

I'm working on #15355 and found some problems with the searches. I will use this ticket to add the patches, one patch for each problem which I have found.

A list with what it not working:

• Comments search doesn't work without JS
• Users search doesn't work with and without JS
• ​http://grab.by/7nC2 I like the idea with the new tab "Search Results (1)", but you will see it only in no-js version and only for themes and plugins search. We should add it for all searches, AJAX search and with no grey bgcolor to be consistent. Or we must respect the active tab like we did it on comments search, so if 'Sticky' tab is active search only through sticky posts and not all as it is yet. What do you think?

So my opionion is to use the same behaviour like comments search.

Related: #15170

15414.plugin.search.patch is the first patch. With it only the plugins of the current status will be searched, same as by the comment searches. It adds also the table navigation for mustuse and dropins plugins, I don't know why there shouldn't be one.
Now the question: Is this needed? Should it be for all searches? If yes, I will do it.

Any relevant UI screenshots for the patch? Just checking

JohnONola: There won't be any UI changes.