Implement a Launcher Validation bulk operation

[ReplicaObscura]

Launchpad doesn't know whether the game your launcher is supposed to launch actually exists or not. Additionally, you could have an invalid combination of options which prevent the launcher from launching and/or monitoring the game properly.

There should be a Launcher Validator bulk oeration run from the Tools menu which shows you a list of all issues with your current launchers.

Additionally, validation should be taken into account when showing the launcher status in the main window.

Finally, don't allow an invalid launcher to actually be built--hide the build button for invalid launchers.