Add a count parameter to String.replace()

[tomsterBG]

A non-breaking change that improves the usability of String.replace() by adding an optional parameter count which limits how many replacements will happen, unlimited by default. (https://docs.godotengine.org/en/stable/classes/class_string.html#class-string-method-replace)

If count is 1 or more, it will be taken into account, otherwise it will not matter and let you do unlimited replacements.

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Currently this method only takes what to replace and forwhat to replace it with, and replaces everything that matches what. This is cool, but sometimes limiting, especially when compared to a language like Python. (https://www.w3schools.com/python/ref_string_replace.asp)

Other languages also have this feature built-in, like Lua. (https://www.luadocs.com/docs/functions/string/gsub) And JavaScript, but flipped on its head. (https://www.w3schools.com/jsref/jsref_replace.asp)

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The specific case when i found this limiting was a creative solution to a Leetcode problem. (https://leetcode.com/problems/maximum-69-number/)

My GDScript solution looks like this:

static func max_69_number(num: int) -> int:
	var stripped = str(num).lstrip("9").trim_prefix("6")
	var size_diff = str(num).length() - stripped.length()
	return int("9".repeat(size_diff) + stripped)

And the Python translation for Leetcode to understand:

class Solution:
    def maximum69Number (self, num: int) -> int:
        stripped = str(num).lstrip("9")[1:]
        size_diff = len(str(num)) - len(stripped)
        return int('9' * size_diff + stripped)

But in Python i can also just do this:

class Solution:
    def maximum69Number (self, num: int) -> int:
        return int(str(num).replace("6", "9", 1))

Sure, this is easy to bypass in my specific case, but considering how scripting languages see it as a necessary feature, i see no problem with having it, plus the optionality of the new parameter makes it compatible.