Formalizes the Use of IPointData

[bigtimebuddy]

This was @andrewstart's (excellent) suggestion to use IPointData instead of IPoint, Point or ObservablePoint. This means we can use more generic objects instead of having to construct one of the Point classes. For instance:

const shapes = new PIXI.Graphics();
shapes.containsPoint({ x: 10, y: 10 });

[codecov-commenter]

Codecov Report

Merging #6704 into dev will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##               dev     #6704   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           15        15           
  Lines          671       671           
=========================================
  Hits           671       671           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 5028949...206bc68. Read the comment docs.