Fixes #1647 and #1651

Adds new 'sanitize' (boolean) option for query_field which when set to false will turn off automatic sanitization for field values, useful for when you want to pre-sanitize your value for a custom 'LIKE' % format; Adds new 'sanitize_format' to define the format string used in $wpdb->prepare() for the value, default is %s or %d for signed/unsigned types; Adds new 'cast' option to customize the exact field casting/aliasing used; Added support for 'field' as a better alternative to the 'key' name going forward; Updated pods_data_field_query filter to send back the final $q field array as processed so now the filter only passes two vars: `apply_filters( 'pods_data_field_query', $field_query, $q )`