D23615: Improve the look of the KWin options KCM UIs

GB_2 added inline comments.

INLINE COMMENTS

> ngraham wrote in actions.ui:26
> Call this "Left click action"

I'll add the word action to the group box headers instead, so the labels aren't so long and there's less duplication.

REPOSITORY
  R108 KWin

REVISION DETAIL
  https://phabricator.kde.org/D23615

To: GB_2, #kwin, #plasma, #vdg
Cc: ngraham, davidedmundson, zzag, #vdg, #plasma, kwin, #kwin, LeGast00n, The-Feren-OS-Dev, sbergeron, jraleigh, fbampaloukas, GB_2, mkulinski, ragreen, jackyalcine, Pitel, iodelay, crozbo, bwowk, ZrenBot, alexeymin, himcesjf, lesliezhai, ali-mohamed, hardening, romangg, jensreuterberg, abetts, sebas, apol, mart