support not well-behaving derived features of Ecore in queries

Short version:

Extend EMF-IncQuery tooling and/or runtime to be able to replace specific path constraints with find structures (e.g. EClass.eAllReferences, EClass.eSuperTypes)

Long story:

From the 20 derived features in Ecore, only one is well-behaving (EGenericType.eRawType), the rest is not.
From the remaining 19, only 3 cannot be described with EMF-IncQuery (defaultValue requires eval and instanceClass is not EMF).
From the remaining 16, only EClass.eIDAttribute depends explicitely on ordering (as it's value will be the first attribute with isID() = true among all supertypes).
The other features can be implemented as queries (as long as the users don't depend on the ordering of the values in their queries, since some of these have very strict algorithms for calculating the order of their values).
These queries are complete and tested, and will be uploaded to Git along with the test cases.
We will have to evaluate the different options for integration (query library support, built-in queries and code generation-time replacement with find, pattern interpretation-time replacing with find, etc.)

viatra / EMF-IncQuery