Fix differences between RayCast2D and RayCast3D documentation

[Mickeon]

Similar to #104354

This PR addresses differences between the documentation of RayCast2D and RayCast3D (within reason). It also fixes an inconsistency that popped up as a result of #101373

This comes with the goal not only making the two consistent, but also reducing the overall amount of strings to localize.

[rburing]

This looks fine now from a physics perspective. Thanks!

I seem to recall a general comment saying that using parameter names as substitutes for words is not the most translation-friendly approach, but I'll leave that for someone else to decide.

[Mickeon]

I seem to recall a general comment saying that using parameter names as substitutes for words is not the most translation-friendly approach, but I'll leave that for someone else to decide.

That may be from me, actually, as well as from others. As personal notes, I wrote as follows:

Avoid using the [param] tag as a replacement for an important subject of the sentence. Ideally, rephrase the sentence as if the parameter names were generic, single-letter words. This makes descriptions easier to localize, while still keeping the [param] tags. Note that parameter names remain unlocalized.

Parameters replacing words something done very commonly across the class reference, and it's a bit debatable. There's no real guideline, too. In my opinion, linking the parameter directly here brings attention to its type without repetition and makes the subject clearer. But there's a lot of occasions where it does, in fact, suck.

[akien-mga]

Thanks!