Initial window width is set to be wider than (default) minimum possible
size. This adds some whitespace and increases width of text inputs
on "tabs" page.

This was made unconditionally, which could increase the width past
screen's right edge on small screens.

It is changed to be at most 2/3 of the screen's width now. Note that
minimum window size is still in effect; the limit affects only
additional width.

(Instructions for X11)

• Run Xephyr -dpi 96 -screen 800x600 :1
• Run DISPLAY=:1 kwin_x11
• Run DISPLAY=:1 ./konsole
• Open edit profile dialog, resize it to minimum allowable size.
• Measure the window size.
• Close Xephyr.
• Run Xephyr -dpi 96 -screen WxH :1, where W is the measured window width + 20, and H is anything larger than measured height.
• Run DISPLAY=:1 kwin_x11
• Run DISPLAY=:1 ./konsole
• Open edit profile dialog

Expected result:
Edit Profile dialog's width should be a bit smaller than Xephyr's
screen