loc_xxx service registration should be compostitional
Currently to register one or more service with location services, one needs to call loc_server_register(server_name) exactly once,
then call loc_service_register(service_name) one or more times.
This makes it impossible for two, independent components in the same task to register services. For example, a library (libui, DDF, libc) cannot register services on its behalf without interfering with the main program or another library.
Note that this is just an API problem and fixing it should not require any fancy changes to IPC mechanisms.