Remove support for Python 3.8

See merge request !127

Fix pylint errors

See merge request !126

XLSXConverter paths validation

See merge request !125

- In export_related.py export() we do not care which Exception is raised & need to continue
- In import_from_xml.py import_xml() the File from which the _checksum is deleted is created within this method
- In table_export.py BaseTableExporter.collect_information(), the method called by _call_find_function is not set, so determining which exceptions may be raised is difficult
- table_importer.py TSVImporter.read_file() only exists for backward compatibility

- New method XLSXConverter._check_path_validity() called in __init__
- New test with test data containing various incorrect paths
- Updated tests and test data to reflect new behaviour

- Remove unnecessary pass, init without effect, unused variables
- Update use of deprecated methods
- Fix used exception not matching documentation
- Ignore logging-fstring-interpolation, variant of logging-format-interpolation

Fix unit tests on Windows

See merge request !124

Parse binary or formula boolean values

See merge request !123