feat(mocks): contacts: working find method with authorized uifaces

Hey :)

I added the `contacts.find` mock method and also added sample images from uifaces.com authorized users so when getting a fake contact we can have a fake avatar too;
Changed the `find` signature to `(fields, options)` arguments which is more close to the cordova API.

scenario : affect some fake contacts to `$cordovaContacts.contacts` then query this database;