AT+DRCSMS should return error if there is no active EDM connection.
AT+DRCSMS should return error if there is no active EDM connection.

Introduce new AVC API to query the session state for a given
DM server.

Resolves: LE-16155
Change-Id: Ie0bda1a959bd483d4dd09f8ee3e320d30cf635b3

legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af