Show the panels and goal dialog at game start

[xsebek]

Describe the bug

[Starting the game paused] gets to a really strange state where the side panels are empty, and the goal is not yet shown, but REPL works.

This is because the Inventory and Info panels update on Frame events, which causes this strange behavior.

I had to deal with this when I was integrating Swarm with Termite, because I forgot to spawn a thread which sends Frame events.

@noyahor in #2076 (comment)

To Reproduce

Run the game with --paused from #2080 and observe the game dialog showing up after one tick.

Alternatively, try running the move tutorial - this may require more retries.

Expected behavior

The UI should always be fully functional at the game start and not wait for events or robots to finish.

This is especially important with the goal dialog, as the player needs to know what to do in the scenario, and a long pause loading the robots would be confusing. This was noted by @byorgey in #2064 (comment).

Screenshots

[byorgey]

I think I understand why this happens. The updateUI function does a whole lot of stuff, including calling doGoalUpdates which is responsible for setting the proper modal. However, updateUI is not called when the game is paused. Perhaps the solution is to split updateUI into two functions, one that should always be called on every frame event and one that should only be called if we just ran the game for some ticks?