[Core] Use Vector for MethodInfo::arguments

[AThousandShips]

One of the bigger offenders when it comes to using a bidirectional data type for random-access purposes, there aren't really any good reasons to use a List here that I can tell, we never do any insertions or erasures on it (one case in Node but it wasn't necessary, and IMO worsened readability)

Nothing should really change here except improving some data management, and locality, and making accessing the arguments easier, performance should be unaffected either way but haven't done any direct testing on that part, but I don't think this data is used in critical paths anyway

Follow-up to:

• Reduce and prevent unnecessary random-access to List #90705

[KoBeWi]

Looks correct.

I wonder if it's worth it to switch to range iterators everywhere, i.e.

int i = 0;
for (const PropertyInfo &pi : method.arguments) {
	// stuff
	i++;
}

Avoids indexing the Vector, although it's cheap anyway.

[AThousandShips]

Worth looking at yeah