Representation + Wires refactor (#498)

**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](#487) 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.

---------

Co-authored-by: Filippo Miatto <[email protected]>

Author: apchytr

.codecov.yml

@@ -5,5 +5,5 @@ coverage:
         target: 89%
     patch:
       default:
-        target: auto
+        target: 99%
         threshold: 0%

.github/workflows/tests_docs.yml

@@ -39,6 +39,5 @@ jobs:
       - name: Run tests
         run: |
           python -m pytest --doctest-modules mrmustard/math/parameter_set.py
-          python -m pytest --doctest-modules mrmustard/physics/ansatze.py
-          python -m pytest --doctest-modules mrmustard/physics/representations.py
+          python -m pytest --doctest-modules mrmustard/physics/ansatz
           python -m pytest --doctest-modules mrmustard/lab_dev

.pylintrc

@@ -28,4 +28,4 @@ ignored-classes=numpy,tensorflow,scipy,networkx,strawberryfields,thewalrus
 # can either give multiple identifier separated by comma (,) or put this option
 # multiple time (only on the command line, not in the configuration file where
 # it should appear only once).
-disable=fixme,no-member,line-too-long,invalid-name,too-many-lines,redefined-builtin,too-many-locals,duplicate-code,too-many-arguments,too-few-public-methods,no-else-return,isinstance-second-argument-not-valid-type,no-self-argument, arguments-differ
+disable=fixme,no-member,line-too-long,invalid-name,too-many-lines,redefined-builtin,too-many-locals,duplicate-code,too-many-arguments,too-few-public-methods,no-else-return,isinstance-second-argument-not-valid-type,no-self-argument, arguments-differ, protected-access

doc/code/lab_dev.rst

@@ -4,7 +4,6 @@ mrmustard.lab_dev
 .. toctree::
     :maxdepth: 1
 
-    lab_dev/wires
     lab_dev/circuit_components
     lab_dev/states
     lab_dev/transformations

doc/code/lab_dev/wires.rst

@@ -4,7 +4,7 @@ mrmustard.physics
 .. toctree::
     :maxdepth: 1
 
-    physics/ansatze
+    physics/wires
     physics/representations
 
 .. toctree::

doc/code/physics.rst

@@ -1,8 +1,8 @@
 Calculations on Bargmann objects
 ================================
 
-.. currentmodule:: mrmustard.physics.bargmann
+.. currentmodule:: mrmustard.physics.bargmann_utils
 
-.. automodapi:: mrmustard.physics.bargmann
+.. automodapi:: mrmustard.physics.bargmann_utils
     :no-heading:
     :include-all-objects:

doc/code/physics/ansatze.rst

@@ -1,8 +1,8 @@
 Calculations on Fock objects
 ============================
 
-.. currentmodule:: mrmustard.physics.fock
+.. currentmodule:: mrmustard.physics.fock_utils
 
-.. automodapi:: mrmustard.physics.fock
+.. automodapi:: mrmustard.physics.fock_utils
     :no-heading:
     :include-all-objects:

doc/code/physics/utils/bargmann_calculations.rst

@@ -0,0 +1,8 @@
+mrmustard.physics.wires
+=======================
+
+.. currentmodule:: mrmustard.physics.wires
+
+.. automodapi:: mrmustard.physics.wires
+    :no-heading:
+    :include-all-objects: