include/msg: Remove log-related functions from test and build modules

include/msg: Remove log-related functions from test and build modules

The "logs" property has been removed from the specification of the
test and build messages, so the functions in the respective modules
that access these properties must be removed as well.
This commit removes the foundry_msg_build_get_logs() and
foundry_msg_test_get_logs() functions and removes the logs parameter
from the foundry_msg_test_new() and foundry_msg_build_new() functions.