Join method for PackedStringArray is not exists

[toby3d]

Godot version: 112884d
OS/device including version: Linux 5.6.7-1-MANJARO
Issue description: After renaming class PoolStringArray (Godot 3.0+) to PackedStringArray (Godot 4.0+), the join method was lost.
Minimal reproduction project:

const uppercase: String = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
const lowercase: String = "abcdefghijklmnopqrstuvwxyz"
const alphabetic: String = uppercase + lowercase
const numeric: String = "0123456789"
const alphanumeric: String = alphabetic + numeric

# Generate fixed-sized string with charset symbols
func string(length: int, charset: String = alphanumeric) -> String:
	randomize()

	var output: PackedStringArray

	while output.size() < length:
		output.append(charset[randi() % charset.length()])

	return output.join("") # The method "join" isn't declared on base "PackedStringArray"

[kuruk-mm]

As you said, this issue is from the rename of PoolStringArray to PacketStringArray, when reduz changed PoolVector to Vector on #36311

I read #36311 and see the changed syntax on the Engine for the joins on the code is:
String(delimiter).join(parts)

e.g in your case: String("").join(output)

So I made a PR with this change to give the ability to join a PacketStringArray to String

Tested code:

extends Node2D

const uppercase: String = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
const lowercase: String = "abcdefghijklmnopqrstuvwxyz"
const alphabetic: String = uppercase + lowercase
const numeric: String = "0123456789"
const alphanumeric: String = alphabetic + numeric

func _ready() :
	print(string(10))
	

# Generate fixed-sized string with charset symbols
func string(length: int, charset: String = alphanumeric) -> String:
	randomize()

	var output: PackedStringArray

	while output.size() < length:
		output.append(charset[randi() % charset.length()])

	return String("").join(output)