Add Open in Browser command to running containers

[philliphoff]

Adds an Open in Browser command to the context menu of running containers in the containers tree view.

The command opens the browser to the first exposed port mapped to the host that likely represents a "web" endpoint. The heuristic works as follows:

• Choose the first port from a prioritized list of ports common to various web stacks with SSL ports preferred over standard HTTP ports (e.g. 443, 80, 3000, 3001, 5001, 5000, 8080, 8081)
• If none found, and if only a single port was mapped, use that port
• Otherwise, if more than one port was mapped, display a quick-pick where the user can select the port.

The "possible" ports as well as the selected port is captured by telemetry, in order to understand how that heuristic could be improved.

[bwateratmsft]

Do we want to leave a cancel step in telemetry here, and/or throw a UserCancelledError?

[philliphoff]

I tried several variants and this seemed to work best (or was the least worst). UserCancelledError doesn't seem technically correct, as the user didn't make a choice--the container just didn't have any ports to browse to. Throwing any other kind of error results in the error dialog with the "report issue" button, which we clearly don't want. You might argue that the command result should be Failed in this case, but I'm not sure it matters from the telemetry analysis point of view. We can pick out this scenario by looking for a completed command, where the possible ports is the empty set and no port was selected.

[bwateratmsft]

For the somewhat similar case where the Azure registry already exists (the one Paul hit), I had it throw a UserCancelledError as a way of getting out of the execution; so it wouldn't be unprecedented.

[karolz-ms]

Looks good!, Just one question...