Introduce expr builder for aggregate function

[jayzhan211]

Which issue does this PR close?

Closes #10545.

Rationale for this change

After this PR, there are two kinds of expression API. One is the normal one like count(expr), convenient for expression that has few arguments. Another is builder mode, useful for expressions that expects multiple kind of arguments, like first_value_builder(expr).order_by().build()

What changes are included in this PR?

Are these changes tested?

Are there any user-facing changes?

[jayzhan211]

I plan to add distinct macro in the follow up PR for count.

[alamb]

This looks super cool @jayzhan211

[alamb]

THanks @jayzhan211 -- I will plan to review this tomorrow.

[jayzhan211]

which means both adding many new functions as well as that they won't work for user defined aggregate functions

I think they can build the function with macro in function-aggregate, so they can have their function with ExprBuilder extension. But then I need to move the macro to datafusion-expr 🤔

maybe make an extension trait

It could be a good idea

[jayzhan211]

Maybe we can just extend function for AggregateFunction 🤔

pub fn call(&self, args: Vec<Expr>) -> AggregateFunction

impl AggregateFunction {
  fn build() -> Expr
}