Fix text selection behavior in reuse panel

The jQuery update broke onDomEvent('focus') in OOjs UI. This is a
workaround which fixes the issue by binding on the input/textarea
elements directly, instead of their parents.

This introduces the annoying side effect that the metadata panel jumps
a bit when the embed HTML text is selected. (Just for that one, yes.
Weird.) Still better for now than no selection at all.

Change-Id: Ifa4c0600d7b4c0c64487596cbcabd5b4f4a12a19
Mingle: https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/638