The previous output of the `nomad server members` command would output a
column named `Protocol` that displayed the Serf protocol being currently
used by servers.

This is not a configurable option, so it holds very little value to
operators. It is also easy to confuse it with the Raft Protocol version,
which is configurable and highly relevant to operators.

This commit replaces the previous `Protocol` column with the new `Raft
Version`. It also updates the `-detailed` flag to be called `-verbose`
so it matches other commands. The detailed output now also outputs the
same information as the standard output with the addition of the
previous `Protocol` column and `Tags`.