[Task] Handle "no target" selection on Dashboard

[andrewazores]

          I say "at least for now" because we should probably actually handle the `NO_TARGET` selection case nicely and allow the dashboard to be created and a skeleton or empty state version of it rendered when the user hasn't selected any target. But even after we have that I think that starting a recording should still be an explicit opt-in action.

Originally posted by @andrewazores in #862 (comment)

[andrewazores]

With the latest changes to the Dashboard and the target selection, this empty view state is only reachable:

1. when the web-client is first opened and no target has ever been selected,
2. when the previously selected target is no longer available (including the case where there are no targets at all)

There is no more ability to explicitly select "no target" and see the empty state. Maybe this doesn't need any additional handling at this point.

[tthvo]

Done in #1303? Editted: Nope, this is about skeleton view when no target is selected. Though, we do have options to clear target selection now.