Summary:
1, Fix for Bug 372169 - GUI angular control for Shadow light source shows incorrect angle (spinbox is correct)

Adobe’s angle selection dial widget differs from QDial by 90 degrees. That creates the inconsistency between settings dialogs and layer effects. In this diff, angle selection is moved into dedicated widget, KisLayerStyleAngleSelector, which solves this problem for all layer style settings dialogs. Also lessens code duplication in this area.

2, Label alignment unification with proper use of QFormLayout

BUG: 372169

Reviewers: #krita, rempt

Reviewed By: #krita, rempt

Subscribers: rempt

Tags: #krita

Differential Revision: https://phabricator.kde.org/D17134