add map, apply, alternative versions of operators

[wallymathieu]

Looks good, I guess the intent here is to present these as module functions for ConcreteCodec?

[gusty]

To me the argument order is a bit unexpected. I'll be in favor of renaming them, for instance map with arguments flipped is called for in Haskell, though here it's a reserved word.

[wallymathieu]

I didn't notice the argument order. Could it be that the argument order was unintentional? @7sharp9

[gusty]

No, it was intentional in order to be able to construct idioms for applicatives/alternatives using forward pipe instead of other operators.

He needed for Falanx, but apparently he solved the operator restriction already.

[wallymathieu]

Should this PR be closed? @7sharp9

[gusty]

Yes