Update for Idris 0.12.1

[BartAdv]

• class/instance -> interface/implementation
• Num -> Num/Neg
• Float -> Double

Stumbled upon weird issue https://github.com/idris-lang/Idris-dev/issues/3291, so this commit also contains the removal of explicit type arguments in the method declaration for VerifiedProfunctor.

[japesinator]

Looks awesome, thanks!