* cherry-pick fd2bc9b
* Return errors when objects are missing references
* Fix import tslint
* Fix failing jest tests
* Fix x-pack integration tests
* Rename ensureReferencesExist to validateReferences
* Fix test naming to use validateReferences
* Update resolve_import_errors API to reflect new type attribute
* Validate references for search type as well
* Clarify comment
* Apply PR feedback
* Modify saved object bulkGet to be able to filter fields
* Apply PR feedback