Experiments and notes
Fix redundant test; more notes
Handle filters[!some:relationship]
Handle filters[!client_integration_id]
Handle filters[some:relationship]=* (exists)
:not_like, :not_begins, and :not_ends
:not
:exists, :not_exists
Discard =* and =nil features
some:relationship:exists and :not_exists
client_integration_id:not
Fix bug when filters[client_integration_id][] (array)
Discard /^! feature from entity filters
Handle filters[some:relationship:field:not]=value
Handle filters[some:relationship][related_entity_field:not]=value
Make rubocop happy
Handle OR of multiple filters[some:meta][]
sanitize_sql() for ILIKE and similar; clean up some comments
Generate unique table alias in filter_on_relationship_exists

Also, stick with "not_*" filter syntax; omit "not-*"
Test :not, :not_like, :not_begins, :not_ends