This PR introduces a fix where unused files in the lookups directory, such as CSV or MLMODEL files that
are no longer referenced by a Lookup YML, could be included in the build of an app.
It also now ensures that CSV referenced by a lookup are syntactically valid CSV.
It also fixes a bug that caused `contentctl test mode:changes` to fail when an mlmodel file had been updated in the lookups directory.
What's Changed
* Fix mlmodel changes bug by pyth0n1c in https://github.com/splunk/contentctl/pull/199
* Parse and validate CSV files by pyth0n1c in https://github.com/splunk/contentctl/pull/200
**Full Changelog**: https://github.com/splunk/contentctl/compare/v4.1.4...v4.1.5