Add new groups for examples packs

Also, remove version numbers. Will make it easier to avoid publishing
the examples packs.

cpp/ql/examples/qlpack.yml

@@ -1,4 +1,6 @@
 name: codeql/cpp-examples
-version: 0.0.2
+groups: 
+  - cpp
+  - examples
 dependencies:
   codeql/cpp-all: "*"

cpp/ql/src/qlpack.yml

@@ -1,6 +1,8 @@
 name: codeql/cpp-queries
 version: 0.0.8-dev
-groups: cpp
+groups: 
+  - cpp
+  - queries
 dependencies:
     codeql/cpp-all: "*"
     codeql/suite-helpers: "*"