[BUG] Function block changes when there's no active client connection are not captured

[Psychlist1972]

Describe the bug

The function block metadata listener is a plugin in the client pipe in the service right now.

Function Block message changes are in-protocol messages. So we have to listen to the messages. That means, there needs to be a connection open when the change happens so we can receive and process the message.

We do protocol negotiation and request function blocks whenever a device is enumerated (plugged in). We keep the connection open for that short period of time to handle that, and then we close it afterwards.

The potential workarounds are:

• Always keep a connection open from the service to the UMP device. This uses more resources, but is probably the best approach. We may need to rethink the current plugin approach and have it sit off in a thread in the transport's endpoint manager instead. Even if there are static function blocks, we still need to listen to other changes like protocol, endpoint name, etc.
• Always re-request function blocks when there's a new connection but no other connection. I see a lot of race conditions with this.

[Psychlist1972]

Closed with release of DP7