Problem with scaling parametrs pluging

[DavideDC95]

Describe the bug
If in plugins it is passed a scaler for the parametrs there is an inconsistency between predict and thruth solution

To Reproduce
pod = POD()
rbf = RBF()
db = Database(param, snapshots.T)
rom = ROM(db, pod, rbf, plugins=[
DatabaseScaler(StandardScaler(), 'reduced', 'snapshots'),
DatabaseScaler(StandardScaler(), 'reduced', 'parameters')
])
rom.fit()
test_param = param[2]
truth_sol = db.snapshots_matrix[2]
predicted_sol = rom.predict(test_param).snapshots_matrix[0]
np.testing.assert_allclose(predicted_sol, truth_sol,
rtol=1e-5, atol=1e-5)

Expected behavior
AssertionError:
Not equal to tolerance rtol=1e-05, atol=1e-05

Output
E Mismatched elements: 2500 / 2500 (100%)
E Max absolute difference among violations: 32.81964758
E Max relative difference among violations: 47.42442793
E ACTUAL: array([ 8.536083, 8.370944, 8.204127, ..., 0.628054, -0.241309,
E -1.047201], shape=(2500,))
E DESIRED: array([ 6.31744 , 6.15722 , 5.99945 , ..., 0.53165 , -0.714494,
E -1.77711 ], shape=(2500,), dtype=float32)

Additional context
For the moment this possibility is removed since in erzb.plugin.scaler.py I added

"
if target == 'parameters': #TODO
raise NotImplementedError("Scaling of parameters not implemented yet.")
"
that block the scaling on parameter. The bug remains to be solved