Add a method to merge two Dictionaries together

[DarcTellier]

Describe the project you are working on

Discord bot using godot engine.

Describe the problem or limitation you are having in your project

I couldn't find a method to merge dictionary's.
Found the solution on this page, works so good that it needs to be in the main repository.
https://godotengine.org/qa/8024/update-dictionary-method

Describe the feature / enhancement and how it helps to overcome the problem or limitation

when I would load a users save file, if I added new elements to the save file dictionary . the new elements will not be added to the loaded file.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

#dictionary merger copy paste below

static func merge_dir(target, patch):
    for key in patch:
        if target.has(key):
            var tv = target[key]
            if typeof(tv) == TYPE_DICTIONARY:
                merge_dir(tv, patch[key])
            else:
                target[key] = patch[key]
        else:
            target[key] = patch[key]

If this enhancement will not be used often, can it be worked around with a few lines of script?

yes

Is there a reason why this should be core and not an add-on in the asset library?

super useful

[Mickeon]

It should probably be called Dictionary.merge().

If it's a reasonable suggestion, but not much of a deal-breaker, I personally think it would be better for it not to be static, so that something along the lines of target.merge(patch) would be possible, and less verbose.

[Calinou]

Duplicate of #1756.