Emergency temporary optimization of national phone number queries.

This patch breaks the semantics of E_BOOK_QUERY_EQUALS_NATIONAL_PHONE_NUMBER
when the query is handled by the SQLite.

The semantics with this patch for national number matching is simply:

  (national_number (A) == national_number (B))

Where the correct semantic is:

  (national_number (A) == national_number (B)) &&
  (has_country_code (A) == FALSE ||
   has_country_code (B) == FALSE ||
   country_code (A) == country_code (B))

This change makes E_BOOK_QUERY_EQUALS_NATIONAL_PHONE_NUMBER very
fast but slightly incorrect, since it ignores the country codes
completely.

Furthermore, the E_BOOK_QUERY_EQUALS_PHONE_NUMBER and
E_BOOK_QUERY_EQUALS_SHORT_PHONE_NUMBER queries are not handled by
SQLite with this patch applied. No matter what the summary
configuration, the exact phone number matches and short phone
number matches will fall back to a slower matching algorithm.

Test case updated to assert the changed behavior in the case
that the summary is configured with phone number indexes.