Optionalexternal_Exact match against the content's external identifier.
Use the full formatted value as it appears in ContentResponse.external_identifier,
e.g. 'vimeo:123456789'.
OptionalmetadataExact key/value pairs to AND-match against content metadata.
OptionaltitleCase-insensitive partial match against the content title.
OptionaluriCase-insensitive partial match against the content URI (external_ref content only).
Search criteria for content search. At least one field must be supplied. All supplied fields must match (AND logic).