Variable explorer search button keeps pressed after hiding the search field with Esc

[ccordoba12]

@dalthviz, this is a small bug I noticed after merging PR #9384: if you hide the search field with Esc, then the search button keeps pressed in the interface, as shown in this screenshot (I took it in the light interface theme because it's easier to see):

However, that shouldn't be the case because it's confusing. So after pressing Esc the search button also needs to appear as not pressed.

[dalthviz]

Should we instead of the Search: label show and x button as in the Find widget? What do you guys think @ccordoba12 @goanpeca ?

Variable Explorer:

Find Widget:

[ccordoba12]

I'm +1 so that users quickly realize that the new field in the Variable Explorer is just like any other search field.

[goanpeca]

I like the idea of keeping the search/find uniform so go for it :-)