Add merged method to allow returning Dictionary after merging

[KoBeWi]

Dictionary merge() is void right now, but it could return itself, so you can chain it or easily use as return value etc.

[akien-mga]

Hm that's not a common pattern in our API. Usually if it returns something it would be merged().
One could make the same case for append() and many other core APIs.

[KoBeWi]

Well I opened this based on how I use my old utility method (I had a GDScript implementation before it was in core). tbh the method would be as useful even if it returned a new Dictionary; I think I originally made it modify the Dictionary, because it's cheaper than copying it (and Dictionary doesn't have any methods that return a new Dictionary).

Tweens have similar API (i.e. it allows chaining method calls on the same object), so it's not unheard of. I just wanted to replace the old method in my project with the new merge() and realized it lacks an important aspect, hence this PR >_>

One could make the same case for append() and many other core APIs.

Well if there is use, they could. Dictionary.merge() is useful for returning a Dictionary with defaults (as I gave example in the doc).

[Mickeon]

I know this is literally two years old but I do agree with the sentiment of Akien of the past.

[KoBeWi]

And I still think some sort of merge and return is useful. I could make it a new method.

[Mickeon]

Mhm!

[KoBeWi]

Should it return a new Dictionary or is it ok if it modifies and returns the same one?

[Mickeon]

Methods such as Vector2's rotated & normalized return a whole new Vector2. So I feel like a theoretically merged should return a new Dictionary as well, perhaps noting that comes at a cost.

[KoBeWi]

Pushed as a new method.
I also slipped a fix for merge() 🙃

[Mickeon]

In my opinion the first parameter could be called with, although unfortunately that'd not be consistent with merge, so hmm.

[Mickeon]

Suggested change

	Creates a new Dictionary, which is a duplicate of this Dictionary merged with the other [param dictionary]. Useful for quickly making Dictionaries with default values.
	Returns a copy of this dictionary merged with the dictionary [param dictionary]. Useful for quickly making dictionaries with default values.

[KoBeWi]

It sounds awkward either way.
"with other dictionary dictionary"
"with other dictionary with"

[Mickeon]

It's about making it easier to translate, as someone did mention to avoid "punning" for that reason.

[Mickeon]

Commit name needs to be changed based on what we discussed above.

Dare I say this method can be nicer to use than merge. Mhm... I wonder who's the silly billy that even added the orig-...

[Mickeon]

This has actually been a-okay for a while, at least documentation wise. I just forgot to approve of it.

Now it's a matter of determining if this is desirable or not (probably yes).

[adamscott]

Let's merge! *starts fusion dance*

[akien-mga]

Thanks!