JS: Update diagnostics IDs for consistency with rules

javascript/extractor/src/com/semmle/js/extractor/AutoBuild.java

@@ -568,7 +568,7 @@ public class AutoBuild {
     }
 
     // DiagnosticLevel level, String extractorName, String sourceId, String sourceName, String markdown
-    diagnostics.get().writeMarkdown(error.getLevel(), "javascript", "javascript/" + error.getId(), error.getName(),
+    diagnostics.get().writeMarkdown(error.getLevel(), "javascript", "js/" + error.getId(), error.getName(),
         message, location);
   }
 

javascript/ql/integration-tests/all-platforms/diagnostics/syntax-error/diagnostics.expected

@@ -10,7 +10,7 @@
   "severity": "warning",
   "source": {
     "extractorName": "javascript",
-    "id": "javascript/parse-error",
+    "id": "js/parse-error",
     "name": "Could not process some files due to syntax errors"
   },
   "visibility": {