Model loader intermediate data

[Nielsbishere]

Is your design request related to a problem? Please describe.
The intermediate data of model loader copies data twice and the copying doesn't use memcpy but uses operator=. It also uses vectors of attributes and not vectors of structs, meaning that you can't memcpy them over but have to swap them around again. This increases load time and also means the same data is duplicated while it doesn't have to.

Describe the solution you'd like
Use memcpy where needed, change assimp wrapper to allow direct copying.

Describe alternatives you've considered
N.A. This doesn't have to be fixed, but it will decrease load times.

Additional context
N.A.

[Nielsbishere]

#222