Terminals not displayed in tree view

[ianthomas23]

Opened terminals do not appear in the TERMINALS section of the tree view on the left-hand side of jupyterlite.

[jtpio]

We probably need to implement another route that lists the open terminals.

[jtpio]

Looks like it's already implemented though:

terminal/src/terminals.ts

Lines 26 to 35 in ccfb585

	/**
	* List the running terminals.
	*/
	async list(): Promise<TerminalAPI.IModel[]> {
	const ret = [...this._terminals.values()].map(terminal => ({
	name: terminal.name
	}));
	console.log('==> Terminals.list', ret);
	return ret;
	}