Merge pull request #14592 from laurocaetano/equality_between_relation_and_collection_proxy

The comparison between `Relation` and `CollectionProxy` should be consistent.

Conflicts:
	activerecord/CHANGELOG.md

Conflicts:
	activerecord/CHANGELOG.md
	activerecord/lib/active_record/association_relation.rb
	activerecord/test/cases/base_test.rb