Add Stroke Selection Edge function
Test Plan:
Bug: https://bugs.kde.org/show_bug.cgi?id=306182
Plan of work: https://phabricator.kde.org/T3281
At now work:
- Gui-prototype
- Line stroke
- Choose size of line selection
- Choose color of line selection and brush selection
- Brush selection
Reviewers: dkazakov
Subscribers: scottpetrovic
Differential Revision: https://phabricator.kde.org/D2302