Allow player authentication in leaderboard

[4ian]

Games (leaderboards):

• Allow passing the connected player to the leaderboard iframe
• Allow communication with the leaderboard iframe to:
  • Get a request to authenticate the player
  • Communicate the result of it
• Fix display of leaderboard iframes in development on iOS
• Add a setting (that can be disabled with an action) to prefer to send a score for the connected player (even if the action to send as an anonymous player is used).

Games (authentication):

• Fix iOS app authentication (postMessage does not work in a Cordova In App Browser, use websocket instead).
• Rework authentication so that the caller code can know when it's done.
• Allow the action that opens the authentication window to wait for the authentication to be done (or closed)

Editor:

• Add option to avoid displaying login buttons in the leaderboards