Fix StackOverflowError on types with self-references

[psteiger]

Description:

When we have self types (implemented by recursive generics), Motif fails with StackOverflowError:

	at com.uber.xprocessing.ext.XTypeKt.hasCollectionType(XType.kt:316)
	at com.uber.xprocessing.ext.XTypeKt.hasCollectionType(XType.kt:316)
	at com.uber.xprocessing.ext.XTypeKt.hasCollectionType(XType.kt:316)
        ...

The following code seems to trigger that condition:

open class BaseRouter<out R : BaseRouter<R, *>, I : BaseInteractor<*, *, *>>(
    interactor: I,
) : Router<I>(interactor)

abstract class BaseInteractor<P : Any, I : BaseInteractor<*, I, *>, R : BaseRouter<R, I>>(
    presenter: P,
) : Interactor<P, R>(presenter) 

public class ConcreteInteractor extends 
    BaseInteractor<EmptyPresenter, ConcreteInteractor, ConcreteRouter>

public class ConcreteRouter extends
    BaseRouter<ConcreteRouter, ConcreteInteractor>
   ...

This PR changes XType.hasCollectionType() implementation to:

1. Not re-process types that were already processed
2. Use a queue instead of recursion (to avoid StackOverflowError for big enough type trees).

Test

Created a local build, built and ran one of our apps with the local build.

[davissuber]

Code looks great; could we add a test?

[davissuber]

Some extra investigation notes regarding the room-compiler-processing library:

• the version are on 2.6.0-alpha02 is closer to the latest version 2.6.1 than I originally thought
• there aren't that much difference in the XType neighborhood between the two versions (based on 5-min of my untrained eyeballing), so bumping the library alone may not solve the stack overflow problem
• however, based on this comment, it seems that hasCollectionType is introduced in part to handle some KSP type equality checks, which even the current version of room-compiler-processing has some special override
  • in other words, maybe we can circumvent the stack overflow problem by changing how we use the room-compiler-processing library (hand-wavy comments made without much context, and possibly a rather involved task)