Fix CdlService getImplementation file location

Updates the `getImplementation` predicate of the `CdlService` class
within the `CDL.qll` library in order to ensure that CDS-related CodeQL
queries are still able to find the `UserDefinedApplicationService`
that implements a given `CdlElement`, even when using "project aware"
CDS compilation that results in a single `.cds.json` file being created
for a given CDS project rather than a 1:1 relationship between each
extracted `.cds` file and its `.cds.json` representation.

Author: data-douser

javascript/frameworks/cap/lib/advanced_security/javascript/frameworks/cap/CDL.qll

@@ -165,8 +165,8 @@ class CdlService extends CdlElement {
   CdlService() { kind = CdlServiceKind(this.getPropStringValue("kind")) }
 
   UserDefinedApplicationService getImplementation() {
-    result.getFile().getRelativePath().regexpReplaceAll("\\.[^.]+$", ".cds.json") =
-      this.getFile().getRelativePath()
+    result.getFile().getRelativePath().regexpReplaceAll("\\.[^.]+$", ".cds") =
+      this.getPropValue("$location").getPropValue("file").getStringValue()
   }
 
   /**