An ObjectType represents the type of an object in a query. An ObjectType is similar to a Class,
except unlike a Class it can be extended to add more information such as a subtype for collection
Classes, a key type for a map class, or a field information for structs.
Note that multiple instances of are allowed of the same type, so ObjectTypes should always be
compared using equals.
Return true if this is a CollectionType. Note that MapTypes, Region types, and array types are
also considered CollectionTypes in the context of the query language and therefore return true
to this method.