Fix/visibility

[NiallOswald]

Description

Closes #3

• Replace visibility polygon algorithm
• Re-enable tests for RDP

Contributor Declaration

By opening this pull request, I affirm the following:

• All authors agree to the Contributor License Agreement.
• The code follows the project's coding standards.
• I have performed self-review and added comments where needed.
• I have added or updated tests to verify that my changes are effective and functional.
• I have run all existing tests and confirmed they pass.

[mathleur]

Thanks for the nice fix @NiallOswald ! Will re-release v0.2.0 with the fixed algorithms :)