Event declaration simplification

[jkruse]

The event declaration method this.event(...) defaults the second argument to df.cCallModeDefault, so there's no point in specifying that value unless the third argument is used.

These can be simplified at the time of writing this:

• Broadcast Channel
• Contact Picker
• Eye Dropper
• Fullscreen
• Network Information
• Notifications
• Page Visibility
• Screen Wake Lock
• Web Share