Implement Densify methods

[peterstace]

Description

These methods return copies of the input geometry that have additional control points inserted such that adjacent control points are at most a fixed distance apart.

This is useful when transforming geometries from one projection to another, since straight lines in one projection are not necessarily straight lines in other projections. The additional control points can help to retain the true shape of curves when they are transformed.

Check List

Have you:

• Added unit tests? Yes.

• Add cmprefimpl tests? (if appropriate?) N/A

• Updated release notes? (if appropriate?) Yes.

Related Issue

• N/A

[peterstace]

Thanks for reviewing @albertteoh , really appreciate it!