Fiddle: Clicking "esc" in Theme search filter closes the preferences window

[vhashimotoo]

Repro:

1. Go to preferences -> general
2. Click the "Choose your theme" box
3. Start searching for something
4. Drop your plans and click "esc" to close this box.

Maybe something for newcomers, just need to disable "esc" when we in the input box.

[mwoodhousemckenzie]

:wave: I took a stab at fixing this problem, I am new to OSS contributions so I am not sure if I went about this correctly 😅

[erickzhao]

@mwoodhousemckenzie I'll take a look at this tomorrow!