Fix opening native targets while they are still building and retry tcp connections to avoid server is still loading page

[ealmloff]

Fixes two different issues:

1. When you press "o" while the server/desktop app is still building, the cli crashes because the exe doesn't exist. The binary is already queued to open so we can just skip this
2. There is a window between when the server has started and when it is reachable. We trigger the reload and proxy once the server starts, but if it isn't reachable, the connection fails. We can retry the tcp connection until we get a good connection and then use that connection to finish the request

Closes #5044
Closes #4981
Fixes #4082
Fixes #5021