Mesh: Save vendor & model info post net create

Mesh: Save vendor & model info post net create

This patch handles following:-

Vendor & model info of local config client
node was not saved to Configuration database
after network is created which caused Network
Load operation to fail due to missing Vendor
& Model Info.

With this patch, all vendor & model info are now
saved to CDB. Dduring Network Load, all data are
fetched from Conf DB and node data is prepared,
which is eventually used to attach to the Network.

Change-Id: Id2d59a6d8bebb32a9a251781b3c0cab494daea1f
Signed-off-by: Anupam Roy <anupam.r@samsung.com>