Add Global Notification Settings

This add the final list of settings in the main setting window as a new page notifications as there are quite a few now. This completes previous work on push rules giving the ability to set the default global rules. Adding keyword rules is also now supported.

This also uses the new mobileform layout. The settings are designed to give some visual feedback as options for whether notifications are on/off, play a sound or are highlighted are chosen. The left icon is designed to mimic the notification dot in the roomlist. The whole mobileform delegate can also be clicked to cycle through the available options.

The rationale for whether an option is available is as follows:

• Highlight is not available if would lead to every message in a room being highlighted
• Keyword notifications cannot be switched off instead the rule is just deleted
• Only keyword rules can be deleted, default rules cannot be touched

There is also rules plumbed in for features that don't exist in neochat yet, i.e. encrypted chats and rooms, calls. I figured I may as well plumb these in and test them my plan was to hide them before merge, they can then be unhidden when the features are complete.