Improved error messages from wraps_ufunc

[tbody-cfs]

1. Improves error message if wraps_ufunc input_units don't match function parameters
2. Improves error message if arguments provided to a wraps_ufunc-wrapped function don't match the expected arguments
3. Improves error message if number of returned values from a wraps_ufunc-wrapped function don't match the number of returned units
4. In case return_keys isn't given as a list, converts to a list.
5. Let's you build a CompositeAlgorithm from a list of algorithm names, as a shorthand for the [Algorithm.get_algorithm(key) for key in keys] pattern.
6. Instead of failing the file write due to unhandled variable sanitization, throw a warning and return UNHANDLED

Example errors

ValueError: Keys for input_units for calc_effective_collisionality did not match the declared function inputs (n.b. order matters!)
i: input_key, func_param
0: average_electron_denssity, average_electron_density DOES NOT MATCH
1: average_electron_temp, average_electron_temp
2: major_radius, major_radius
3: z_effective, z_effective

ValueError: Number of returned values (1) did not match length of units_mapping (2)
i: return_key, returned_value
0: effective_collisionality, <xarray.DataArray 'average_electron_density' (dim_average_electron_density: 40,
                                              dim_average_electron_temp: 30)> Size: 10kB
array([[0.00981582, 0.00807611, 0.00676363, ..., 0.00069563, 0.00065933,
        0.00062581],
       [0.01963165, 0.01615222, 0.01352725, ..., 0.00139126, 0.00131866,
        0.00125162],
       [0.02944747, 0.02422833, 0.02029088, ..., 0.00208689, 0.001978  ,
        0.00187744],
       ...,
       [0.3730014 , 0.30689229, 0.25701795, ..., 0.02643434, 0.02505507,
        0.02378129],
       [0.38281722, 0.3149684 , 0.26378158, ..., 0.02712999, 0.02571442,
        0.02440711],
       [0.39263305, 0.32304452, 0.27054521, ..., 0.02782563, 0.02637377,
        0.02503294]])
Coordinates:
  * dim_average_electron_density  (dim_average_electron_density) float64 320B ...
  * dim_average_electron_temp     (dim_average_electron_temp) float64 240B 5....
1: test, MISSING

ValueError: Number of returned values (2) did not match length of units_mapping (1)
i: return_key, returned_value
0: effective_collisionality, <xarray.DataArray 'average_electron_density' (dim_average_electron_density: 40,
                                              dim_average_electron_temp: 30)> Size: 10kB
array([[0.00981582, 0.00807611, 0.00676363, ..., 0.00069563, 0.00065933,
        0.00062581],
       [0.01963165, 0.01615222, 0.01352725, ..., 0.00139126, 0.00131866,
        0.00125162],
       [0.02944747, 0.02422833, 0.02029088, ..., 0.00208689, 0.001978  ,
        0.00187744],
       ...,
       [0.3730014 , 0.30689229, 0.25701795, ..., 0.02643434, 0.02505507,
        0.02378129],
       [0.38281722, 0.3149684 , 0.26378158, ..., 0.02712999, 0.02571442,
        0.02440711],
       [0.39263305, 0.32304452, 0.27054521, ..., 0.02782563, 0.02637377,
        0.02503294]])
Coordinates:
  * dim_average_electron_density  (dim_average_electron_density) float64 320B ...
  * dim_average_electron_temp     (dim_average_electron_temp) float64 240B 5....
1: MISSING, <xarray.DataArray 'average_electron_density' (dim_average_electron_density: 40,
                                              dim_average_electron_temp: 30)> Size: 10kB
array([[3.2, 3.2, 3.2, ..., 3.2, 3.2, 3.2],
       [3.2, 3.2, 3.2, ..., 3.2, 3.2, 3.2],
       [3.2, 3.2, 3.2, ..., 3.2, 3.2, 3.2],
       ...,
       [3.2, 3.2, 3.2, ..., 3.2, 3.2, 3.2],
       [3.2, 3.2, 3.2, ..., 3.2, 3.2, 3.2],
       [3.2, 3.2, 3.2, ..., 3.2, 3.2, 3.2]])
Coordinates:
  * dim_average_electron_density  (dim_average_electron_density) float64 320B ...
  * dim_average_electron_temp     (dim_average_electron_temp) float64 240B 5....

[hassec]

Some small comments. Would you mind making sure to run pre-commit locally to fix the formatting error the CI is complaining about?

[hassec]

Great stuff, thanks Tom 👍