All expressions should have empty parameters initialisers about faunadb-swift

[mtnbarreto]

The goal of the named parameters is readability.
A developer doesn't need to type the parameters name since Xcode intellisense does the work.

Anyway I'm ok with removing the first parameter name for the more generic constructor.

[erickpintor]

Just to be clear, I not referring only to the first named parameter. I meant to remove all named parameters if their types are Expr.

Expr itself is never mentioned in our documentation. It ended up being a concept we've created to help us design the drivers. Therefore, have named parameters such as refExpr makes no sense for the user.

Our functions are quite small and simple so, the user will most likely to compose a few of them in each query. We should try to make composed Expr clear and concise.

For the other syntax sure or convenient initialisers, I'm fine using named parameters.

[erickpintor]

@mtnbarreto has pointed out that Apple will require named parameter in further versions of Swift. Therefore, it doesn't seems wise to remove them.

Anyway, I think we should at least avoid parameter names with expr on them.