so that one should use:
swh vault rpc-server
as in other swh packages.
The deprecated swh-vault command should still work as expected.
Also improve config file loading behavior as well as the help for this.
Resulting help msg looks like:
$ swh vault rpc-serve -h
Usage: swh vault rpc-serve [OPTIONS]
Software Heritage Vault RPC server.
If the CONFIGFILE option is not set, the default config file
search will be used; first the SWH_CONFIG_FILENAME environment
variable will be checked, then the config file will be searched
-C, --config-file CONFIGFILE Configuration file.
--no-stdout Do NOT output logs on the console
--host HOST Host to run the server
--port PORT Binding port of the server
--debug / --no-debug Indicates if the server should run in
-h, --help Show this message and exit.