That is to use the new `tractor.msg.types.Aid` struct to pull the
`brokerd` info from the `tractor.Channel.aid: Aid` attr as well as more
generally handling the new `Channel.raddr.proto_key: str` and no longer
assuming a TCP IPC transport; this per the recent `tractor.ipc`
subsys which adds multi-IPC-transports!
Downstream tweaks to match,
- use an "opt-in" field set to display in the `brokerd` info pane in
`.ui._feedstatus.mk_feed_label()`.
|_ also add some todos and drop some seemingly unneeded form sizing
calcs?
- tweak `.ui._label` to allow not using markdown, though ended up not
doing that since it looked too plain..
0bd8cd1882