Add rad seed/unseed commands

[maninak]

We need two new VS Code commands in the Command Palette to tell our local Radicle node how to seed (or untrack) specific Radicle repos.

Acceptance Criteria:

1. new command to run rad seed <RID>
   • no support for extra flags --alias and --scope unless implementing to optionally define them is relatively quick
2. new command to run rad unseed <RID>
3. no troubleshooting on error, other than notifying the user (and logging) (handled separately by Ask user to connect to seed node, if extension can't find repo id to seed / clone #57)

[gsaslis]

only as VS Code commands in the Command Palette?

yes.

also in the UI? Where?

Tracking is a top-level action, so it would probably be the start of a new interaction path. For the time being, I don't think it's worth exposing this to the UI through a separate button, but I can see a future version where - as heartwood evolves - we have a richer interface around "exploring" and finding new nodes to track (e.g. "friends of friends"). We should probably wait for more developments on that front to understand how we should approach this.

For now, the single command should be enough.

what if the RID isn't doesn't resolve via the connected seeds/nodes?

under the scope of this issue, we should only show the output / error message from the rad CLI command.

should we offer to resolve e.g. ask the user for a node URL and connect to it and replay? Maybe make that a new ticket to work on before this one?

this does sound like a new ticket, yes, but, no, we shouldn't work on it before this one. Tracking is a necessary action that we want to have soon - so we can move to Radicle - whereas the experience improvement will be necessary when we want to start attracting users.