Implemented easy clip alignment

Previously, there was no way to easily align clips inside
or outside of the view.

There existed alignment settings for title clips, but no easy way
to align video clips.

To address this issue, a new AlignmentEditor widget was made and placed
in the transformation properties expander.

Fixes #2279
1 job for easy_clip_alignment_feature in 10 minutes and 57 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #699793
flatpak
build

00:10:57