Pathfinding3d

- Minor bug fixes
- More tests added

- New tests added for diagonal movements
- LRU caching for heuristics
- Updated documentation and examples
- Node class has additional attributes for heap caching
- Replicated simple heap structure inspired from [python-pathfinding](https://github.com/brean/python-pathfinding/pull/54), [original author](https://github.com/peterchenadded).

- Based on version v1.0.7 of [python-pathfinding](https://github.com/brean/python-pathfinding/commits/main/)

- Updated Grid initialization to have better error messages
- URLs updated to point to the new repository
- Better documentation

Enabled weights for BiAStarFinder

Adds:

- Type hints
- Sphinx minimal autogenerated documentation
- codecov badge and workflow