Optional Reference Types and References to Optional Types are represented with the same TypeID

[dsainati1]

Current Behavior

There is currently an ambiguity in the creation of type IDs between references to optionals and optional references. I.e., a ReferenceType(OptionalType(T)) will be rendered as &T?, and OptionalType(ReferenceType(T)) is also rendered as &T?.

Expected Behavior

We should produce non-ambiguous TypeIDs for these two cases.

TODOs:

• What should the representation for these be?
• How and when should we migrate existing TypeIDs to the new format?
• Check whether or not the typeIDs of these values are stored here

Steps To Reproduce

N/A

Environment

See https://github.com/onflow/cadence/pull/3232

[dsainati1]

This blocks #3232