net: coap: Add coap_next_block_for_option function

Add a function to update the coap block context from a
packet, according to the block option enum provided.

The existing coap_next_block does not handle block1 transfers
properly because we need to inspect the block1 option
returned by the server. This function is reworked to make use
of the newly introduced one.

Signed-off-by: Pieter De Gendt <pieter.degendt@basalte.be>
2 files changed