Refactor the Olympus client application due push notification changes

[ognjenns]

The push notifications should be handled in the Application delegate class; We need to have communication with push data and resctomm sdk
therefore we need to change the applications sdk initialization, callbacks and business logic.

[ognjenns]

After investigation, we realized that refactoring for push will include refactoring the almost all view controllers. We will put it on ice for now.
Here is the rough ides what needs to be done:

Current logic include RCDevice in view controllers.

The idea is to create new singleton class RCDeviceHandler and heleper classes (if we need them).
Currently, the device connection or RCDevice instance is passed through the majority of the view controllers.
I think we should remove that;
Instead I would handle all business logic inside RCDeviceHandler.
Communication between the RCDeviceHandler and view controllers will be done via protocols defined on RCDeviceHandler.
Also, intruducing RCDeviceHandler will help on handling push notifications.

Some of the changes (roughly):

• KeypadViewController -> it will have RCDeviceHanlder instance and it will call methods for sending digits (we will not give the RCConnection to viewController)
• ContactDetailsTableViewController -> We will remove Device (this view controller was use the instance only to give it via segue to the MessageTableViewController)
• CallViewController -> Also, remove de device from it and handle only layout button (mute, hangup...) call the methods on the RCDeviceHandler
• MainTableViewController, MessageTableViewController -> Remove callbacks and device; Impelement on RCDeviceHandler;
• SettingsTableViewController, SipettingsTableViewController, ICESettingsTableViewController -> Remove RCDevice and intruucde RCDeviceHandler