Fix numerical transforming

[NilsHMeier]

When transforming values to numeric datatype, some transformations and formats are not correctly parsed.

Current behaviour

from DataHandling import convert_to_numerical
values = ['1.000.250', '1.000,25', '1,000.25']
convert_to_numerical(values)
# Out: [1000.25, 1000.25, 1000.25]

Expected behavior

from DataHandling import convert_to_numerical
values = ['1.000.250', '1.000,25', '1,000.25']
convert_to_numerical(values)
# Out: [1000250, 1000.25, 1000.25]