Please bring back the search currently installed addons input.

[hit_fm]

I suppose in the `about:addons` page, an input should be provided to search currently installed addons instead of always jump to addons website to search. It's basic and important for users.

[jscher2000]

In a recent update, Ctrl+F (on Mac, Command+F) was modified so it calls up regular page search instead of putting the cursor in that search box. When that was under consideration, I don't think anyone proposed to add a second search form field to the page...