Consolidate primitive collections across relational and Cosmos (#33456)

* Consolidate primitive collections across relational and Cosmos

This change starts using the EF8 primitive collection infrastructure for primitive collections in Cosmos. This involves adding support for nested collections and read-only collections.

The main challenge here is supporting all the different collection types when, for example, `List<List<string>>` cannot be cast to `IEnumerable<IEnumerable<string>>`. To support this, we use exact collection types in snapshots, and we use non-generic methods in the nested comparers and serializers.

General dictionary mapping still not supported.
No extensive query testing done yet.

Model building and change tracking for #30713
Fixes #25364
Fixes #25343
Part of #4179
Fixes #31722

* Remove dead files

* Updates based on review feedback

Author: ajcvickers