refactor: replace LineOrPoint struct with enum

[RobWalt]

• I agree to follow the project's code of conduct.
• I added an entry to CHANGES.md if knowledge of this change could be valuable to users.
• Tests still pass

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This small PR swaps out the LineOrPoint struct with an enum approach. It doesn't change the functionality of the type but the use of it should be much more readable now.

@rmanoka pinging you since it is mainly your code and I would appreciate a review if you find the time. I'm trying to make improvements step by step but I need to understand the code better (hence this PR). Are PRs like this ok for you?

[michaelkirk]

I don't see any errors in the translation, and it "feels" nicer, but I defer to @rmanoka about wether we want to merge a refactor like this to the sweep algo.

[rmanoka]

lgtm too; can you fix the lint and fuzz CI errors?

[RobWalt]

Just looked into it. The error is

 --> geo/src/algorithm/sweep/line_or_point.rs:128:32
    |
128 |         T::Ker::orient2d(*self.left, *self.right, other)
    |                                ^^^^ method, not a field
    |

I just double checked and my code doesn't include this anymore. Could it be related to some kind of cache or dependency from geo to itself?

[RobWalt]

Here are my changes, the error isn't even showing the code from the previous version 👀 I rg-d over the whole repo and I couldn't find the code that was mentioned in the error message ...

[michaelkirk]

CI updates your branch locally before running the tests to make sure they are compatible with what's in the main branch. Looks like the code in question was merged since your branch was created.

Can you either rebase and force push or merge main into your branch and address the issues?

[RobWalt]

Done 👍