feat: add super() implementation

[ElectricalBoy]

Summary

This PR adds BaseClass.super().

How did you test this change?

included tests

[hjpalpha]

what are the perf implications of this?

[ElectricalBoy]

what are the perf implications of this?

negligible: see leagueoflegends:User:ElectricalBoy/Sandbox/PerfTest1 and leagueoflegends:User:ElectricalBoy/Sandbox/PerfTest2

[mbergen]

What's the usecase for this?
In case of single level inheritance like in the linked PR, you imported the Base anways, and could do

function Child:fun()
    return Base.fun(self)
end

to call an overridden function of the Base, right?

[ElectricalBoy]

What's the usecase for this? In case of single level inheritance like in the linked PR, you imported the Base anways, and could do

function Child:fun()
    return Base.fun(self)
end

to call an overridden function of the Base, right?

function Child:fun()
	return self:super():fun()
end

I think that this is more readable as it clearly shows with super that the method of parent class is called; I mean, it's a widely used keyword in OOP already.
Also, I think Base.fun(self) really is a workaround for absense of super in our Class implementation