[Core] Fix line filter for scenario outlines

[mpkorstanje]

Broken by #1804. While covered by unit tests, the unit tests were broken by
a change in the way feature identifiers were parsed. When parsing a feature
path relative paths are expanded to full file uris. This resulted in the uri
of the pickle not matching the uri provided by the test. As a result all pickles
were accepted regardless of the filter used.

Fixes: #1980

Checklist:

• I've added tests for my code.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[coveralls]

Coverage decreased (-0.007%) to 85.956% when pulling 642fa92 on core-fix-line-filter-for-scenario-outline into 844e8c1 on master.