[Feature Request] Being able to open a list that shows all executables on the system and being able to add them

[ghost]

So I want to be able to open a menu that lists all executables on the system and there you can select some executables,then click "next" and then do what https://github.com/lutris/agora/issues/58 wants:

I want a feature that pops up a window when a user drops an .exe file into the Lutris window. The window will contain 2 things, first, a field a user can type a name for that game. The second thing would be asking if the dropped file is the game's executable or an installer.

If it's a game executable, a game entry will be made, into the game list, the name will be what user entered, the runner will be set to Wine. In Game options, the executable path will be auto set to the path of that .exe the user dropped. Wine prefix will be set to the Default installation folder, followed by the game name or whatever.

If it's a game installer, a game entry will be made, into the game list, the name will be what user entered, the runner will be set to Wine. Wine prefix will be set to the Default installation folder, followed by the game name or whatever. The exe file will be run automatically in that prefix and the user will have to follow the installation to it's end. After the installation is done, it could technically auto set the the executable path based on the start menu shortcut that the installer created. (Lutris can filter out any shortcut that has 'uninstall' in the name and anything that leads to a web url or a help page. It can have something in place that picks the shortcut that leads to just the .exe of the game). Either that or ask the user to manually find the .exe.

That would make adding games so much easier,cause I hate it to search for the games and add them manually after downloading.

[ghost]

Also a button to check all executables would be cool