IrTypeparameter resolution

[i-walker]

addresses #749, as in adding new members and utilities to resolve IrTypeParameters through the IrTree and recursively walking the parent hierarchy for potentially unsubstituted type parameters.

Conceptually, it enables the functionality found in IrTypeSubstituter, which is specialized for IrValueParameters for IrMemberAccessExpressions, by breaking down its API and behavioral aspects.

In a further PR, this can be used to refine the targetType, when extension proofs are injected, that have missing type information. But the technical debt persists to improve the detection of that very targetType consistently for all expressions.

An example is here - given that List has an Functor instance:

call-site: 
listOf(2).fmap{ it * 2 }
// in this case the call-site is broken down by each "call expression"

expression	unsubstituted type	missing type information	resolved Type
listOf(2)	List<T>	T	Int
fmap { it * 2}	B from fmap	B	Int

To further resolve fmap the remaining Type parameters in the parent hierarchy need to be resolved of Functor and Functor.Ops, which is:

expression	unsubstituted type	missing type information	resolved Type
fmap { it * 2}	Functor.Ops<F, A>	F, A	F -> ListOf<Int>, A -> Int
fmap { it * 2}	Functor<F>	F	ListOf<Int>

implying that ListOf<A> is an typealias for Kind<List(_), A> and established as an isomorphism to List<T>

This is necessary, because the expected value- and target type for an extensionproof injection at the aforementioned call-site would be:

• valueType: List<Int> or worst case: List<T> <- detection works
• targetType: Functor<F, A> <- which can now be refined to Functor<ListOf<Int>, Int>
  But currently the target Type is not resolved to Functor<F, A>

[i-walker]

Here I was also keen on return Map<IrTypeParameter, Either<IrSimpleType, IrTypeArgument>>, depending on how we use it in other places, besides Extensions.
But we can change it to one or the other, it's not fixed.

[danimontoya]

thank you @i-walker looks good! 🙌

[raulraja]

👏 thanks @i-walker !