net: lwm2m: move library internals to net_app APIs

This is the final stage of moving the LwM2M library internals to
the net_app APIs.  This means we can support DTLS and other
built-in features in the future.  All of the logic for
establishing the network connection is removed from the sample
app.

Signed-off-by: Michael Scott <michael.scott@linaro.org>
6 files changed