Changes to Mention Rate Over Time

added ApiFilters subschema #2 to the filters request property allOf list

the filters request property type changed from object to no type

removed the request property filters/competitor_ids

removed the request property filters/end_date

removed the request property filters/location_ids

removed the request property filters/models

removed the request property filters/prompt_ids

removed the request property filters/prompt_status

removed the request property filters/prompt_type

removed the request property filters/start_date