Make it store its internal `zap.Logger`'s level. Also, make all the
components to accept internal `logger.Logger` instead of `zap.Logger`; it
will simplify future refactor.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
1. Do not require a request to be signed by the container owner if a
bearer token is missing
2. Do not check the system role since public requests are not expected to
be signed by IR or a container node (unlike the object requests)
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>