Bug 1070823 - [Bluetooth][Settings] bluetooth panel support BT v2 API

* Functionality ready item:
  - Enable/Disable
  - Visible
  - Device List (Remote/Paired)
  - Search (startDiscovery)

* Functionality not ready item:
  - Pair
  - Connection of paired device
  - Timeout visible, Rename with new layout
  - Icon type of device item
nit: remember to update the file name