AddressBook integration + UI and Behavior improvements.

Details:

- Control now loads contacts from address book after requesting permission.
- Added model class THContact
- Used custom cell view for easier UI customization.
- Added neat circular checkbox to the left side of the contact cell.
- Added circular contact images.
- Text filter field and table view resize using animation for smoother feel.
- Bar button on the top right is disabled by default and enabled when there is at least 1 contact selected.
- Keyboard is dismissed when tapping outside the filter text field.
- TODO: Implement contact details view