Support IEnumerable navigation properties with Add/Remove/Contains methods/delegates

[ajcvickers]

Most of the infrastructure is in place to support collection navigation properties that implement IEnumerable but not ICollection. The part missing is the ability to configure the model with appropriate methods or delegates to use for manipulating the collection. Keep in mind that whatever is done here should be something that doesn't conflict with the idea of creating a compiled model which can then be incrementally loaded.

[andrebaltieri]

+1

[yanjustino]

+1

[divega]

@ajcvickers I see this bug is actually about supporting IEnumerable navigation properties with out-of-band add, remove and contains methods/delegates. Then I guess we already work with IEnumerable<T> navigation properties with a runtime instance that can is ICollection<T>, correct?

[hidegh]

+1 a must for v1.1!

[ajcvickers]

See also #21262