["Request"] Add extract and embed properties to Prism

[ferranpujolcamins]

Description

Bow offers the possibility to create a Prism providing an extract and an embed functions. For consistency, Prism should allow such functions to be retrieved from a Prism.

It might help people who is not used to the Either formulation of Prisms.

Potential implementation

public extension Prism where S == T, A == B {
    var extract: (S) -> A? {
        getOrModify >>> \.orNil
    }

    var embed: (A) -> S {
        reverseGet
    }
}

Modules

Optics

[truizlop]

LGTM, please open a PR with that. There is a way of creating a Prism with embed and extract, but not a way of retrieving these properties.