Bezier-rs: Add calculations for area and centroid of subpaths (#1729)

* add code to calculate area and centroid of subpath

* change library to poly_it

* add a demo of area and centroid

* modify algorithm to consider negetive area as positive

* add code for manipulating polynomials in bezier-rs

* remove `poly_it` dependency and use custom Polynomial

* formatting floats to skip last zero

* add debug mechanism

* collect both intersection points instead of one

* fix test and cargo fmt

* apply minimum separation filtering in self_intersection and use better endpoint filtering algorithm

* remove debug mechanism and cargo fmt

* consider the subpath as closed for intersection calculation

* add documentation for polynomial.rs

* impl display for Polynomial

* make area always positive

* add missing docs

* fix test and cargo fmt

* Naming/formatting code review

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Co-authored-by: Keavon Chambers <keavon@keavon.com>

libraries/bezier-rs/src/lib.rs

@@ -5,6 +5,7 @@ pub(crate) mod compare;
 mod bezier;
 mod consts;
 mod poisson_disk;
+mod polynomial;
 mod subpath;
 mod symmetrical_basis;
 mod utils;