Refactor save/load 1d

[fzeiser]

Working on percistency for some classes, and looking through this realized that the Vectors are saved as a one column vector, appending values and energies. I think this is rather ugly, much easier if we have two columns, energy and values.

ompy/ompy/filehandling.py

Lines 266 to 270 in 77e30bf

	def save_numpy_1D(values: np.ndarray, E: np.ndarray,
	path: Union[str, Path]) -> None:
	mat = np.append(values, E)
	assert mat.size % 2 == 0
	np.save(path, mat)

@vetlewi : Do you by any chance use save/load already? I don't want to break your code ;P, but otherwise I'd like to change it. It's not really important, but still 😄

[vetlewi]

I don't think so, no.