before this change, we used the lower-case CMake build configuration name for the rust profile names. but this was wrong, because the profiles are named with the scylla build mode. in this change, we translate the $<CONFIG> to scylla build mode, and use it for the profile name and for the output directory of the built library. Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>