Improve code stability

[dynafide]

In order to improve the stability of Resurgence as a library, all calls to panic!() .unwrap() and todo!() should be rewritten to pass results to the calling application. I'm creating this issue to keep track of progress.

[StandingPadAnimations]

I think for .unwrap() we can use a try catch statement and handle the error internally

[StandingPadAnimations]

todo!() statements will not be part of the first stable release unless something odd happens

[dynafide]

.expect(err) should also be avoided before stable release.