Fix moving buttons when seach text is inserted
BUG: 406993
FIXED-IN: 5.73
By setting a maximum width we can be sure that the layout does not move when the clear button gets shown. And when we resize the dialog the sidebar does not get resized anyways.
Also the placeholder text gets changes to "Search ...", because the old text can't be fully displayed.
The line edit got moved one column to the left. We still have the issue that the searchfield is kindof short and because it is organized in a grid layout we can't just make it wider. IMO this change makes sense but it is kindof a VDG discussion.
The new QtQick dialog does this with a searchfield in the top bar, which works really well. And because this QWidgets dialog is kind of on life support I am against a more difficult redesign and just settle for this minor improvement and the bugfix :-).