DECL Revamp (WIP/Hacking)

[peterstace]

Description

This is a WIP/Hacking branch for a DCEL revamp. It's not really intended to be merged (I'll raise changes in smaller PRs instead).

Check List

Have you:

• Added unit tests? Yes.

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

• Updated release notes? (if appropriate?) N/A

Related Issue

• https://github.com/peterstace/simplefeatures/issues/465
• https://github.com/peterstace/simplefeatures/issues/464
• https://github.com/peterstace/simplefeatures/issues/304
• https://github.com/peterstace/simplefeatures/issues/302
• https://github.com/peterstace/simplefeatures/issues/300

Benchmark Results

N/A