Move from ssl_*2.c to ssl_test_lib.h:
* The inclusion of the config header file (identical).
* The fallback definitions of platform functions (almost identical:
server2 also had snprintf and the order and whitespace was slightly
different).
* The compilation guards checking that required options are
enabled (tweaked to make them common, with MBEDTLS_SSL_{CLI,SRV}_C
separated out).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
ab7ce96d7b