* Add KQL functionality in the find function of the saved objects
wip
rename variable from KQL to filter, fix unit test + add new ones
miss security pluggins
review I
fix api changes
refactor after reviewing with Rudolf
fix type
review III
review IV
for security put back allowed logic back to return empty results
remove StaticIndexPattern
review V
fix core_api_changes
fix type
* validate filter to match requirement type.attributes.key or type.savedObjectKey
* Fix types
* fix a bug + add more api integration test
* fix types in test until we create package @kbn/types
* fix type issue
* fix api integration test
* export nodeTypes from packages @kbn/es-query instead of the function buildNodeKuery
* throw 400- bad request when validation error in find
* fix type issue
* accept api change
* renove _ to represent private
* fix unit test + add doc
* add comment to explain why we removed the private
d95c47f776