Before this commit the search would search for phone numbers that contained a part of a string. The mobile phone would only look at exact matches so if we'd search for '0492700' the only result would be contacts with this exact match. After this commit every mobile phone that contains '0492700' will match and be shown. This allows for quickly finding customers by a partial mobile, just like the phone number does.

closes odoo/odoo#43629

Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>