Switch aktualizr usage of rvi_lib to the one provided by GDP

Currently a copy of rvi_lib is included by aktualizr.

We would prefer to have aktualizr depend on rvi_lib as it is included as a separate package (and probably remove rvi_lib from aktualizr repository?).

The meta-rvi layer has the build instructions: recipes-connectivity/librvi/librvi_git.bb

(This should be scheduled after GDP 12)