Allow passing glam vector types as vertex attributes (#6442)

Allow passing `Vec`s of glam vector types as vertex attributes.
Alternative to #4548 and #2719

Also used some macros to cut down on all the repetition.

# Migration Guide
Implementations of `From<Vec<[u16; 4]>>` and `From<Vec<[u8; 4]>>` for `VertexAttributeValues` have been removed.
I you're passing either `Vec<[u16; 4]>` or `Vec<[u8; 4]>` into `Mesh::insert_attribute` it will now require wrapping it with right the `VertexAttributeValues` enum variant. 

Co-authored-by: devil-ira <justthecooldude@gmail.com>

Author: tim-blackbird