Error while parsing optional columns in snappy pull-sheets

[eudesbarbosa]

Issue
The pull sheet routine fails during mapping if columns that should be optional have unexpected values.

Error while mapping SEX:

I 220909 09:00:32] Starting to pull sheet...
[I 220909 09:00:32]   Args: Namespace(verbose=False, config=None, sodar_server_url=None, sodar_api_token=None, cmd='snappy', snappy_cmd=<function run at  >, base_path='/path/to/project/', yes=False, dry_run=False, show_diff=True, show_diff_side_by_side=False, library_types=[])
[I 220909 09:00:32] Will start at /path/to/project
[I 220909 09:00:32] Loading data sets from /path/to/project/.snappy_pipeline/config.yaml
[I 220909 09:00:32] Loaded 1 data sets, 1 with SODAR UUID
[I 220909 09:00:32] Pulling for 1 datasets
Traceback (most recent call last):
  File "path/to/env/bin/cubi-tk", line 33, in <module>
    sys.exit(load_entry_point('cubi-tk', 'console_scripts', 'cubi-tk')())
  File "/path/to/cubi-tk/cubi_tk/__main__.py", line 123, in main
    res = cmds[args.cmd](args, parser, subparsers.choices[args.cmd] if args.cmd else None)
  File "/path/to/cubi-tk/cubi_tk/snappy/__init__.py", line 130, in run
    return args.snappy_cmd(args, parser, subparser)
  File "/path/to/cubi-tk/cubi_tk/snappy/pull_sheets.py", line 304, in run
    build_sheet(config, dataset.sodar_uuid),
  File "/path/to/cubi-tk/cubi_tk/snappy/pull_sheets.py", line 264, in build_sheet
    MAPPING_SEX[source.sex.lower()],
KeyError: ''

Error while mapping AFFECTED:

[I 220909 09:34:05] Starting to pull sheet...
[I 220909 09:34:05]   Args: Namespace(verbose=False, config=None, sodar_server_url=None, sodar_api_token=None, cmd='snappy', snappy_cmd=<function run at  >, base_path='/path/to/project', yes=False, dry_run=False, show_diff=True, show_diff_side_by_side=False, library_types=[])
[I 220909 09:34:05] Will start at /path/to/project
[I 220909 09:34:05] Loading data sets from /path/to/project/.snappy_pipeline/config.yaml
[I 220909 09:34:05] Loaded 1 data sets, 1 with SODAR UUID
[I 220909 09:34:05] Pulling for 1 datasets
Traceback (most recent call last):
  File "path/to/env/bin/cubi-tk", line 33, in <module>
    sys.exit(load_entry_point('cubi-tk', 'console_scripts', 'cubi-tk')())
  File "/path/to/cubi-tk/cubi_tk/__main__.py", line 123, in main
    res = cmds[args.cmd](args, parser, subparsers.choices[args.cmd] if args.cmd else None)
  File "/path/to/cubi-tk/cubi_tk/snappy/__init__.py", line 130, in run
    return args.snappy_cmd(args, parser, subparser)
  File "/path/to/cubi-tk/cubi_tk/snappy/pull_sheets.py", line 304, in run
    build_sheet(config, dataset.sodar_uuid),
  File "/path/to/cubi-tk/cubi_tk/snappy/pull_sheets.py", line 265, in build_sheet
    MAPPING_STATUS[source.affected.lower()],
AttributeError: 'NoneType' object has no attribute 'lower'

To Reproduce

1. Create snappy project for case described in Duplicate sequencing #62
2. Run: cubi-tk snappy pull-sheets

Expected behavior
Sample sheet should creation shouldn't fail.

Additional context
NA