Only show initial config screen if the HS path is not detected

[jleclanche]

• HSTracker should default to the system language (with the usual fallbacks)
• The HS path can be autodetected in various ways and locations
• If the HS path is found, we can also figure out the HS language (it's in the config somewhere)

User should never have to set up their HS language. Only show that screen if the path is not autodetected, so that users can input it themselves (but even that should be a rare scenario as I believe we can even read the path that the Battle.net agent wrote Hearthstone to).