No equivalent of join() in PackedStringArray

[KoBeWi]

Godot version

b1063a7

System information

W10

Issue description

join function is rather important for String arrays, but strangely, it's missing in the new PackedStringArray. It was there in PoolStringArray

Steps to reproduce

1. var array = PackedStringArray(["hello", "world"])
2. var hellow = array.join()
3. You expected "hello world", but it was me, Nonexistent function!
4. :(

Minimal reproduction project

No response

[qarmin]

This function now is reversed in Godot 4.0

PackedStringArray(req_godot).join('.') -> '.'.join(PackedStringArray(req_godot))

[KoBeWi]

Most of the languages I used used the old way, i.e. Array.join(). Maybe we could allow both options or at least document in PackedStringArray how to join it.