improve request validation

[alexskr]

following query results in 500 error instead of the 400
/search?q=melanoma&ontologies[]=SNOMEDCT&ontologies[]=LOINC

this particular call not constructed correctly but API should improve request validation to handle this appropriately.

/srv/ontoportal/ontologies_api/releases/20240927040643/helpers/application_helper.rb:186:in `block in ontologies_param'
/srv/ontoportal/ontologies_api/releases/20240927040643/helpers/application_helper.rb:186:in `map'
/srv/ontoportal/ontologies_api/releases/20240927040643/helpers/application_helper.rb:186:in `ontologies_param'
/srv/ontoportal/ontologies_api/releases/20240927040643/helpers/application_helper.rb:314:in `ontology_objects_from_params'
/srv/ontoportal/ontologies_api/releases/20240927040643/helpers/application_helper.rb:202:in `restricted_ontologies'
/srv/ontoportal/ontologies_api/releases/20240927040643/helpers/search_helper.rb:139:in `get_term_search_query'
/srv/ontoportal/ontologies_api/releases/20240927040643/controllers/search_controller.rb:21:in `process_search'
/srv/ontoportal/ontologies_api/releases/20240927040643/controllers/search_controller.rb:8:in `block(2 levels) in <class