Rename struct/aabb2d.h functions to match aabb2d.h, add tests

[duarm]

closes #429

Problem

Missing _sizev and _diag from structs/aabb2d

Solution

Rename _size to _diag, add missing _sizev, I've also added a test file for the aabb2d api

Discussion

The struct API usually returns the struct instead of a dest parameter, aabb2d and box however, still have a dest parameter on some functions, as we do not have an aabb2d struct, just an array. Since the _sizev is a new function, I've opted for returning the vec2s instead of a dest parameter. Should I keep it this way or make it a dest parameter for consistency?

void glms_aabb2d_sizev(vec2s aabb[2], vec2s *dest);
# or
vec2s glms_aabb2d_sizev(vec2s aabb[2]);

[recp]

Hi @duarm,

No dest param in structure api, it looks good!

Since it seems Draft, can we merge it?

[duarm]

I was planning on adding more tests, but that can be done later, let's merge

[recp]

@duarm the PR is merged, thanks for your contributions 🚀