Add physics interpolation docs to 4.3

[skyace65]

This PR adds the physics interpolation docs from 3.6 to the 4.3 branch. This is mostly a copy and paste with the following changes:

• The camera example from one page was removed as it was a 3D example.
• the bottom of the 2D and 3D page was mostly removed. it now just states that interpolation isn't supported for particles.
• The existing images were converted to webp, and the one picture of the editor was re-done, all images have gone through webp compression.
• Notes added on each page stating that physics interpolation does not work in 3D
• Removed info on MultiMesh from the advanced physics interpolation page since those methods don't exist in 4.3
• Updated the project settings links for physics FPS since the setting was renamed in 4.x
• Changed a reference for camera (3D camera) to "a node" (line 151 on using physics interpolation)

I'm keeping the 2D and 3D page mostly as is because the 2D information on that page is still useful, it would be time consuming to remove everything 3D related, and it would seem mildly pointless since the 3D information will be relevant again in a future update. Though I'm open to doing more changes if anyone thinks it's necessary.

[skyace65]

@rburing Could the 3D camera example in these docs be re-worked for a 2D scene? And if so how heavily would it have to be modified? I'm trying to figure out if it should be altered or just removed.

[rburing]

@skyace65 I would remove all of it for 4.3 for simplicity.

Also there is no get_global_transform_interpolated or interpolation of 2D particles in 4.3.

We can add back the camera example for 4.4 when 3D physics interpolation is merged.

cc @lawnjelly

[skyace65]

@rburing it's ready for review now.

[rburing]

I would really remove all details about 3D, since nothing is merged on that front. Minimal docs are fine to start with. I'll be glad to update the docs for 3D when the time comes, but at the moment I'm on vacation.

[lawnjelly]

Agree with @rburing on simply removing the details of 3D, especially in the 2D and 3D physics interpolation section. I actually only added that section after adding 2D to emphasize the differences.

So perhaps just titling it 2D physics interpolation for now and only including 2D info would be good.

[tetrapod00]

So, 3D physics interpolation (https://github.com/godotengine/godot/pull/92391) was merged into 4.4.

Is it still the right approach to start with this PR targeting 4.3 that only discusses 2D and removes all mentions of 3D? There are notes about the lack of 3D support that will only be relevant for a single minor version.