Remove derivative from rendy

[Veykril]

Removes the derivative dependency from crates that are using it, as mentioned in #203, replacing it with manual implementations of the corresponding traits.

[codecov-io]

Codecov Report

Merging #210 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #210   +/-   ##
=======================================
  Coverage   87.57%   87.57%           
=======================================
  Files           6        6           
  Lines         169      169           
=======================================
  Hits          148      148           
  Misses         21       21

Impacted Files	Coverage Δ
util/src/types/vertex.rs	86.3% <ø> (ø)	⬆️

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[Frizi]

I like the idea, but before we commit to writing impls manually i'd like to see actual numbers. Can you measure the build times from before and after this change?

[Veykril]

Sure, and as it turns out the times are pretty much the exact same as it seems, regarding just building the rendy crates without the dependencies I got 20.03s and on a second try 24.53s for 9e7cb21 and 24.29s for my branch, and with all dependencies its 1m 08s for both, though for my branch derivative is still being build as dependency due to winit using it. So it seems derivative itself doesnt do much.

[Frizi]

In that case I would prefer to get rid of failure first. Derivative macros are really useful for maintenance reasons, so if there is no real difference in build times I'd like to keep them.

[Veykril]

Ye figured, definitely the smarter choice to stick with derivative then for the time being. Will try to see what removing failure will do and if it improves the times or not, depending on that I'll do a PR or comment in issue #203 with my findings.

[Frizi]

Okay, thank you for doing that @Veykril :)