Store ArrayMesh path in RenderingServer for use in error messages

[clayjohn]

Fixes: #84875

This only works for ArrayMeshes and not for custom meshes created through the RenderingServer API (unless the uses sets the path manually).

Its the same approach we have used for textures and shaders, so it is nice to keep the API consistent.

[BastiaanOlij]

I like this!

I wonder that if no file path is available, we could also check if the user has set a resource name. I know its not common for users to set that, but in case they do, it'll atleast give them a hint?

[YuriSizov]

Thanks!

I wonder that if no file path is available, we could also check if the user has set a resource name. I know its not common for users to set that, but in case they do, it'll atleast give them a hint?

That makes sense to me, but I assume it also needs to be done to textures and shaders, so I think we can do this as a follow-up.

[alfredbaudisch]

As of 4.2.2 RC 1, the issue of "Attempting to use a shader that requires tangents with a mesh that doesn't contain tangents." being spammed is still presently HEAVILY. Literally 1000s of these warning messages.

[akien-mga]

That's expected, this PR was merged two weeks ago in the master branch (4.3.dev) and hasn't been cherrypicked for the 4.2 branch yet.

[akien-mga]

Cherry-picked for 4.2.2.