PHRAS-676 #time 3h

new : returns facet on "type" (image, video, ...)
new : query on pseudo-field "type", ex:  "type:image"

lib/Alchemy/Phrasea/SearchEngine/Elastic/Search/FacetsResponse.php

@@ -75,6 +75,8 @@ class FacetsResponse implements JsonSerializable
                 return sprintf('collection:%s', $this->escaper->escapeWord($value));
             case 'Base':
                 return sprintf('database:%s', $this->escaper->escapeWord($value));
+            case 'Type':
+                return sprintf('type:%s', $this->escaper->escapeWord($value));
             default:
                 return sprintf('r"%s" IN %s', $this->escaper->escapeRaw($value), $name);
         }