Lasso tool for Brush selections (POC)

[palucdev]

Current Behavior

We don't have any advanced tools that were mentioned when the project stared. Especially Lasso Tool.

Expected Behavior

Working tool based upon idea of Adobe Photoshop Lasso Tool: Youtube example.
User using lasso tool can easily mark contour of given shape working on slice and then fill it with color resulting in brush selection.
In tool menu it should be available as standalone 'Lasso tool'.

As this kind of tool can be tricky to implement, we should consider few approaches and choose the one that is least impactful.

Additional comment (optional)

Feel free to expand upon the idea of lasso tool. Should we make it standalone (not resulting in brush selection)? Or maybe something different?