Make MDM Agent wait until interfaces are ready before starting CBMA

As I realize it might not be clear what the issue is and how this PR is solving it:

Just after booting up, some interfaces might still not be ready for socket operations when the MDM Agent is started.
As a result, when CBMA gets launched in them and try to perform socket operations (such as creating the multicast listener), the OS will raise an exception and the CBMA instance will gracefully stop
The MDM Agent still doesn't have functionality to monitor the state of the interfaces and restart CBMA in them if needed, so this interface will remain without CBMA running on it

:shell:

tiiuae / mesh_com