bug: Robot stops advertising itself when another device has the same name

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Overview

If a robot has the same name as another device on the network, the robot will stop advertising itself to the Opentrons App and other users of our discovery-client.

Steps to reproduce

1. Have two robots.
2. Make sure both robots are advertising themselves.
   • They should both show up and be connectable in the Opentrons App.
   • On macOS, dns-sd -B should show them both.
   • The discovery client (cd discovery-client && yarn discovery browse) should show them both.
3. Rename one robot to foo.
   • You can do this with the 6.0 beta Opentrons App. Or, you can manually issue an HTTP POST to robot_ip:31950/server/name {"name": "foo"} with a tool like curl or Postman.
4. Rename the other robot to foo, also.
5. Wait a few moments.

Current behavior

• In the Opentrons App, one of the robots will drop to the "Unable to locate this robot" state. (You may need to hit Refresh List to trigger this.)
• dns-sd -B will only show one of the robots.
• yarn discovery browse will only show one of the robots.

Expected behavior

Both robots should remain discoverable through the Opentrons App, dns-sd, and yarn discovery browse.

Bug details

• On the client side, robot discovery works by browsing DNS-SD services. (Specfically, _http._tcp ones.)
• DNS-SD services have a human-readable name, the instance name. We keep the robot's DNS-SD instance name in sync with the name that we expose over HTTP.
• Apparently, when DNS-SD services are advertised over mDNS, as ours are, the instance name needs to be unique on the network. Services are supposed to resolve the conflict by selecting new names for themselves, like My Printer (2).
• The way we're using Avahi, it doesn't take care of this deconfliction for us. When it detects a name conflict, it will stop advertising until we give it a new name that doesn't conflict.
• We never catch this case or attempt to choose a new deconflicting name. So, the robot will not advertise itself again until it's rebooted.

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Solution paths

Flesh out our D-Bus code

Flesh out our D-Bus code to feed Avahi a new name whenever it detects a conflict.

Delete our D-Bus code and configure Avahi with a static service file

See #10199.