AggregateUDF expression API design

File an issue to track the design of UDAF API

Perhaps something like 
```rust
// form `FIRST_VALUE(a ORDER BY b)`
let agg_expr = AggregateUDF::call(first_value())
  .args(col("a"))
  .order_by(vec![col("b"))
  .build()?;
```

_Originally posted by @alamb in https://github.com/apache/datafusion/pull/10492#discussion_r1599967446_
            