resolveNetworkAddress: Listen for close instead of exit; Fix FailedApp theme

[ravicious]

We had another instance of a flaky resolveNetworkAddress test. We already tried to deal with this in the past (#25249), but we might have as well fixed one or zero problems at that time while there was another lurking under the surface.

resolveNetworkAddress receives a child process. It listens to both process.stdout.on('data') and process.on('exit'). resolveNetworkAddress resolves when the child process prints a specific string to stdout or rejects with an error if the process exits before printing the string.

The problem is that the fake process we use in tests exits almost immediately after printing since there's nothing else to do.

To guarantee that resolveNetworkAddress processes the data listener before the exit listener, we have to listen for close instead of exit as the docs say):

The 'close' event is emitted after a process has ended and the stdio streams of a child process have been closed. This is distinct from the 'exit' event, since multiple processes might share the same stdio streams. The 'close' event will always emit after 'exit' was already emitted, or 'error' if the child failed to spawn.

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That's the original issue fixed by this PR. However, while testing the fix in dev version of Connect, by doing os.Exit right before the port is logged and making the app failed to start, I discovered another problem. The error component AKA FailedApp was not being rendered successfully.

Because of the theme changes, the Card component, used in FailedApp, now requires a theme to be rendered. I thought the issue was simply that Card.defaultProps were incorrect, but after fixing that I discovered that there's a slew of other components which also require a theme or typography but don't have those props set by default.

Instead of fixing them one by one, I decided to simply add a static theme provider so that those components can render. I picked the dark theme so that we don't flash people with a white screen in case of an error.

[zmb3]

Thanks for the fix!

[public-teleport-github-review-bot]

@ravicious See the table below for backport results.

Branch	Result
branch/v11	Failed
branch/v12	Failed
branch/v13	Create PR