Representation + Wires refactor

[apchytr]

Context: One bottleneck currently in Mr Mustard is that Representation and Wires are treated separately when they are in fact very closely related. Here is presented an alternative implementation based on the Merging Representation and Ansatz PR. In this, we now have a single Representation class that contains the ansatz, the wires and a dictionary mapping wires to their respective representation.

To consider: Remove ArrayAnsatz and only use PolyExp?

Description of the Change:

• Introduced the new Representation class.
• Introduced RepEnum class.
• What is currently on develop as Ansatz and Representation is replaced with just Ansatz.
• All CircuitComponents are initialized with a Representation and a name. Exposed classes are still initialized with modes where they make use of the new from_modes class method.
• Renamed bargmann.py and fock.py to bargmann_utils.py and fock_utils.py
• Renamed fock to fock_array

Benefits: We now have an object responsible for managing multi representations and keeping track of what wire each representation is. Fewer classes to maintain (6 -> 4). Clearer separation of responsibilities. Much cleaner codebase.

[ziofil]

What a truckload of good work!
thanks Anthony 🥇

[ziofil]

amazing work 🚀

[ziofil]

re-approved

[ziofil]

I like this PR so much I'm happy to keep re-approving it ^^