Index project permissions when indexing commits

Two project permission fields (visibility_level and repository_visibility_level) should be sent in addition when indexing commit documents. The indexer should accept these fields as command line arguments (like the project_id is currently provided) to avoid making extra calls pull them when the caller should have easy access to the data.

Use json for the command line argument and name it something generic additional_data to keep backwards compatibility with previous versions of the indexer. The additional_data should be merged with the data sent to Elasticsearch for indexing.

• Create a new tag once this MR is merged which will be used to update the version of the indexer used in gitlab