Bug 877718 - [Messages] Contact's correct phone number and type is displayed r=julienw

https://bugzilla.mozilla.org/show_bug.cgi?id=877718

- Rename Utils.compareDialables => Utils.probablyMatches
    - normalizes with navigator.mozPhoneNumberService.normalize if possible
    - otherwise fallback to previous matching strategy (no non-digit => digit replacement)

- Update navigator.mozContacts.find desktop "mock" to also normalize when searching numbers

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>