JS: Add metadata to dbscheme and stats

Author: asgerf

javascript/ql/lib/semmlecode.javascript.dbscheme

@@ -1192,3 +1192,9 @@ configLocations(
 );
 
 @configLocatable = @config | @configName | @configValue;
+
+/*- Database metadata -*/
+databaseMetadata(
+  string metadataKey: string ref,
+  string value: string ref
+);

javascript/ql/lib/semmlecode.javascript.dbscheme.stats

@@ -28260,5 +28260,41 @@
 </dep>
 </dependencies>
 </relation>
+<relation>
+<name>databaseMetadata</name>
+<cardinality>1</cardinality>
+<columnsizes>
+<e>
+<k>metadataKey</k>
+<v>1</v>
+</e>
+<e>
+<k>value</k>
+<v>1</v>
+</e>
+</columnsizes>
+<dependencies>
+<dep>
+<src>metadataKey</src>
+<trg>value</trg>
+<val>
+<hist>
+<budget>12</budget>
+<bs/>
+</hist>
+</val>
+</dep>
+<dep>
+<src>value</src>
+<trg>metadataKey</trg>
+<val>
+<hist>
+<budget>12</budget>
+<bs/>
+</hist>
+</val>
+</dep>
+</dependencies>
+</relation>
 </stats>
 </dbstats>