[KATC] Update config schema

This PR makes the following config updates:

Rename source column to path to be more consistent with our e.g. dataflatten tables, which also return a path column
Rename source to source_paths for clarity; additionally, make it an array rather than a single string to allow for matching against multiple patterns
Rename query to source_query to disambiguate from the query column we use elsewhere
Rename platform to filter to clarify that we may have other types of filters in the future
Update config structure to be a list of tables instead of a map, so that K2 is able to send down config definitions for all tables instead of filtering by platform; launcher handles the filtering instead
To support the above, move the table name inside the table config

These changes were made in roughly this order; it is possible to review commit-by-commit if that's easier.

kolide / launcher