Added draw_rect_rounded()

[DallinTG]

Hi this is a draw rect rounded proc it is very similar to how raylib did it because i was referencing raylib the entire time i was working on it but i did make one improvement from the raylib version this one can rotate and have a origin. I hope you find this helpful in some way if you have any questions about it just ask me.

[karl-zylinski]

Thanks, I might take a look at this code when I implement some more drawing procs (after Beta 2 is done).

I changed this PR to a draft as it does not follow these rules: https://github.com/karl-zylinski/karl2d/blob/master/pull_request_rules.md (the rules didn't exist when you made the PR, so don't worry about that, you didn't do anything wrong, just informing you now).

[DallinTG]

I believe it is ready now. Please let me know if something needs to be changed.
I fixed the spaces
I made the math much more readable
I have updated things to follow the rules

[DallinTG]

The points are now in local space “{0,0}”
Then all of the transformations are done to them. This then allowed me to easily put part of it in a very simple loop. It also made all of the other math follow a similar structure meaning that if you understand one part of the code it will be easier to understand the rest of the code.