FEATURE: actions for rotate/scale/mirror/shear selection

Now Rotate/Scale/Mirror/Shear Layer actions also support
handling a selection. If there is a selection active, then
the action will transform selected content only.

Now there are also 8 new actions, that will rotate/scale/
mirror/shear *all* layers without resizing the image. These
actions can also handle selections.

Animation Note:

* when no selection present, the actions transform *all*
  the frames of the layers in question

* when there is a selection active, only current frame
  is transformed

BUG:365595
Ref T3920
CC:kimageshop@kde.org