Fix handle invalid controller attributes (#740)

* Move controller attribute validation from DMF to Repository

Rational: Constraint validation on key & value of a map is currently not
supported by EclipseLink Maven Plugin. Therefore, this check has to be
done by hawkBit. The check is required for both APIs (DMF + DDI).

* add tests for attribute validation
* update tests

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* Review findings

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* * Add custom exception for invalid target attributes
* Add integration tests for DDI and DMF

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* * rename exception

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* * rename test steps

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* Fix value size

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* Ensure constraints are validated correctly

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* Introduce review findings

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

* fix sonar finding

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

hawkbit-core/src/main/java/org/eclipse/hawkbit/exception/SpServerError.java

@@ -44,6 +44,11 @@ public enum SpServerError {
      */
     SP_REPO_CONCURRENT_MODIFICATION("hawkbit.server.error.repo.concurrentModification", "The given entity has been changed by another user/session"),
 
+    /**
+     *
+     */
+    SP_TARGET_ATTRIBUTES_INVALID("hawkbit.server.error.repo.invalidTargetAttributes", "The given target attributes are invalid"),
+
     /**
      *
      */