libedata-book: Improve national phone number matching

libedata-book: Improve national phone number matching

e_phone_number_compare() and e_phone_number_compare_strings()
had different opinion how well "1234" and "234" match within
NANP regions. First considered them a national significant
number match as it interpreted the leading "1" as country
calling code, the later didn't. The former interpretion fits
better our E.164 normalization we do in the SQLite backend,
therefore we adopted that approach.

This also introduces e_phone_number_compare_strings_for_region().

https://bugs.freedesktop.org/show_bug.cgi?id=59571