[zeditor] Can't give focus to Combo Flag search box

[Asuna Yuuki Nagato]

The search boxes on:

• The 'Select Enemy' window (accesible via Quest->Enemies)
• The 'Select Item' window (accesible via Quest->Items)
• The Equipment tab of the 'Init Data' window (accessible via Quest->Init Data->Equipment)

are also affected.

The "View Script Slots" window when the Alphabetize checkbox is checked (accessible via ZScript->Compile ZScript...->Slots) does gain focus when clicking it, but the visual feedback that this is the case is a dotted line around the listbox above instead of the search box.