Introduce LogURIGenerator helper function in cio package. It is used in
the restart options, like WithBinaryLogURI and WithFileLogURI.
And restart.LogPathLabel might be used in production and work well. In
order to reduce breaking change, the LogPathLabel is still recognized if
new LogURILabel is not set. In next release 1.5, the LogPathLabel will
be removed.
Signed-off-by: Wei Fu <fuweid89@gmail.com>
