Store operations in enum(s)

[KyGost]

Resolution to: #142

Ideally after: #144

Should be unit enums.
Usage is entirely(?) within Recipes

[KyGost]

Should implement

• From<&str>
• Into<String>/Serialize
• Execute

[KyGost]

Should implement From<&str>, Into<String>/Serialize

[KyGost]

Maybe functions should have different traits/enums for different numbers of variables, rather than just accepting Vec?

Maybe have:

• Execute1
• Execute2
• ...
• ExecuteVec

And functions may implement multiple.

Use macro to create?