refactor!: split helicity module (#87)

* refactor!: use formulate for expressions
* refactor: expose generate_clebsch_gordan
* refactor: expose generate_kinematic_variables
* refactor: extract _state_to_str
* refactor: extract assert_two_body_decay
* refactor: hide name_generator member
* refactor: improve readability group_transitions
* refactor: make StateWithID public
* refactor: make TwoBodyDecay public
* refactor: make generate_wigner_d public
* refactor: make get_transition_label public
* refactor: move extract_ang_mom to TwoBodyDecay
* refactor: move get_helicity_info to decay
* refactor: remove __attempt_int_cast
* refactor: remove _transition_info module
* refactor: rename __register_parameter_couplings
* refactor: rename generate_amplitude_name
* refactor: rename generate_coefficient_name
* refactor: simplify __generate_intensity function
* refactor: switch to sympy.Rational
* style: improve definition order helicity module
* style: improve method order helicity.naming
* style: remove redundant pylint ignores
* style: sort kwargs attr.s
* test: write more unit tests and match with definitions

docs/usage/amplitude.ipynb

@@ -120,7 +120,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "If we now use the {meth}`.HelicityAmplitudeBuilder.generate` method of this builder, we get an amplitude model without any dynamics:"
+    "If we now use the {meth}`.HelicityAmplitudeBuilder.formulate` method of this builder, we get an amplitude model without any dynamics:"
    ]
   },
   {
@@ -129,7 +129,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "model_no_dynamics = model_builder.generate()"
+    "model_no_dynamics = model_builder.formulate()"
    ]
   },
   {
@@ -199,7 +199,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "model = model_builder.generate()"
+    "model = model_builder.formulate()"
    ]
   },
   {

docs/usage/dynamics/custom.ipynb

@@ -217,7 +217,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Now, just like in {ref}`usage/amplitude:Build SymPy expression`, it's simply a matter of plugging this builder into {meth}`.set_dynamics` and we can {meth}`~.HelicityAmplitudeBuilder.generate` a model with this custom lineshape:"
+    "Now, just like in {ref}`usage/amplitude:Build SymPy expression`, it's simply a matter of plugging this builder into {meth}`.set_dynamics` and we can {meth}`~.HelicityAmplitudeBuilder.formulate` a model with this custom lineshape:"
    ]
   },
   {
@@ -228,7 +228,7 @@
    "source": [
     "for name in reaction.get_intermediate_particles().names:\n",
     "    model_builder.set_dynamics(name, create_my_dynamics)\n",
-    "model = model_builder.generate()"
+    "model = model_builder.formulate()"
    ]
   },
   {

docs/usage/interactive.ipynb

@@ -123,7 +123,7 @@
     "model_builder.set_dynamics(initial_state_particle, create_non_dynamic_with_ff)\n",
     "for name in reaction.get_intermediate_particles().names:\n",
     "    model_builder.set_dynamics(name, create_relativistic_breit_wigner_with_ff)\n",
-    "model = model_builder.generate()"
+    "model = model_builder.formulate()"
    ]
   },
   {