tests: net: lib: coap: testing new return values of coap_packet_parse()
tests: net: lib: coap: testing new return values of coap_packet_parse()

Adding tests for new return values of coap_packet_parse.

Signed-off-by: Sagar Shah <bec6b94297f55eeb9e7cfeaaece2077658a4c7ba@legrand.us>

galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr