net: lwm2m: Update LwM2m server object to v1.1

Added Kconfig configurable choise option for enable Server
object version 1.0 or 1.1.

Server Object v1.1 enable by default server initiated bootstrap
trigger when CONFIG_LWM2M_RD_CLIENT_SUPPORT_BOOTSTRAP is enabled.

Signed-off-by: Juha Heiskanen <juha.heiskanen@nordicsemi.no>