Allow the uri passed to various entrypoints to itself contain most of the configuration for that entrypoint by using the RFC 3986 uri format to allow for additional parameters to be used in configuring and selecting those entrypoints. Also bring over network_utils from oslo since it provides a more compliant url splitting support. Part of blueprint persistence-uris Change-Id: I8e5d8584d2cac4f9b338fa155f220cdfd52bb7d9