Crawling through inventory results: companions

There is a possibility of having a CompanionRelationship table with associated CompanionParameter results. It may be good to consider adding the ability to crawl through and fetch companion parameters for any companion that is found.
This may be a bit tricky, but probably not impossible.

An option I'm thinking is add a dictionary with the Relationship name and the Column to use for matching, then associated tables to use with that matched column value. This can allow for more flexibility if the name of the relationship table is different and there is more than one associated table of values.

Start by reviewing the CompanionRelationship and CompanionParameter table definitions and how inventory results currently fetch related data. Clarify the relationship-name and matching-column configuration, including support for multiple associated tables. Done means companion parameters can be crawled from discovered companions without breaking existing inventory-result behavior.

Written by the indexing model from the issue text.