Error when importing sigma rule with single quote

[lo-chr]

Describe the bug
In certain cases, the import of Sigma rules fails, especially when they contain characters like '.

To Reproduce
Steps to reproduce the behavior:

1. Download triggering Sigma rule like proc_creation_lnx_gtfobin_vim.yml
2. Run tsctl import-sigma-rules [location_of_rule]/proc_creation_lnx_gtfobin_vim.yml
3. See error:

yaml.parser.ParserError: while parsing a flow mapping
  in "<unicode string>", line 1, column 1:
    {'title': 'Vim GTFOBin Abuse - L ...
    ^
expected ',' or '}', but got '<scalar>'
  in "<unicode string>", line 1, column 151:
     ... 'Detects usage of "vim" and it\'s siblings as a GTFOBin to execu ...

Expected behavior
Successful import of rule

Additional context
I think the problem here lies in line 250 to 255 of sigma_util.py:

timesketch/timesketch/lib/sigma_util.py

Lines 250 to 255 in 57c585c

	rule_yaml_data = yaml.safe_load_all(rule_text)
	for doc in rule_yaml_data:
	parser = sigma_collection.SigmaCollectionParser(
	str(doc), sigma_conf_obj, None
	)

in connection with line 32 to 36 of tools/sigma/parser/collection.py in the sigmatools package:

The function is called twice on the same input (once in sigma_util.py, once in collection.py). The "double-escaping" seems to lead to a ParserError.