Ignore Byte Order Mark (BOM) when reading in a file

[houlihaj]

Using Ubuntu 22.04, when reading in a Lookup Table (LUT) .csv file using the _parse_lut_into_list method in the lut_cmd.py module, an unexpected and undesired Byte Order Mark (BOM) is prepended to the first element in the LUT list.

A solution to the bug is suggested here:

https://stackoverflow.com/questions/59810796/why-is-there-a-preceding-ufeff-in-the-file-read

clld/clldutils#65