Publish on crates.io

[ahupp]

It would be nice if the onvif-rs crates were available on crates.io, so they can participate in the usual semver upgrade processes. There's an existing, essentially unused "onvif" name you might be able to get ownership of.

Related, many of the dependent crates have names that aren't namespaced, e.g "transport" instead of "onvif-transport" etc. This is both somewhat unclear, and makes naming conflicts more likely.