Add a test suite and fix some bugs.

Code modifications:

* [Fix] adts in TransverseMapSector
* ComplexData.name_and_coefficients_table is now a staticmethod.
* Extend WakeField to "mixed" componenets (xydip, yxdip, ...).
* Small fix/improvements for rf.py (CavityResonator for n_bin=1)
* [Fix] WakePotential.check_sampling method.
* [Fix] Sweep.plot method.
* Add Element.track_bunch_if_non_empty decorator.
* Modify Bunch.binning to add a return_full_length optional parameter.
* Modify Mpi.share_distributions for n_bin=1.
* Modify TransverseSpaceCharge to work with track_alive = True.
* Modify WakePotential for n_bin=1 and use track_bunch_if_non_empty decorator.
* [Fix] IntrabeamScattering for nonuniform fills with Beam.mpi_switch == False
* Modify PhysicalModel to return errors if needed.
* Update BeamIonElement

Project management:

* Update pyproject.toml and poetry.lock with pytest-mock
* Add assert_attr_changed test function.