bookkeeper should handle ipv6 ip address

*Problem*

Currently bookie doesn't handle ipv6 ip address very well. when a bookie advertises itself, it might put an ipv6 address with bookie port, the ipAddress:port pair will be recorded in formats like `xxxx:a06:ttttf1:fef:0:yyyy:3181`, which will fail the client parsing. we need to make sure when bookie advertising ipv6 ip address, it put `[]` into the ip address and client are able to parsing that format.

Related Issue: apache/incubator-pulsar#1953

Start by tracing where a bookie advertises its address and where the client parses the recorded ipAddress:port value; the issue provides no file or test names. Use related issue apache/incubator-pulsar#1953 for context, and consider the work done when IPv6 addresses are recorded with brackets and the client can parse that format.

Written by the indexing model from the issue text.