[Dokan] Add support to multiple postcode ranges.

functions.php

<?php
use WeDevs\DokanPro\Shipping\ShippingZone;

add_filter( 'dokan_vendor_shipping_is_available', function( $is_available, $package, $shipping ){

    $seller_id = $package['seller_id'];
    $destination_postcode = isset( $package['destination']['postcode'] ) ? $package['destination']['postcode'] : '';
    $destination_postcode = wc_normalize_postcode( $destination_postcode );

    if ( empty( $seller_id ) ) {
        return false;
    }

    $zone      = ShippingZone::get_zone_matching_package( $package );
    $locations = ShippingZone::get_locations( $zone->get_id(), $seller_id );

    foreach ( $locations as $location ) {
        if( 'postcode' === $location['type'] ){
            $code = $location['code'];
            if ( strstr( $code, '...' ) ) {
                $range = array_map( 'trim', explode( '...', $code ) );

                if ( 2 !== count( $range ) ) {
                    return $is_available;
                }

                list( $min, $max ) = $range;

                // If the postcode is non-numeric, make it numeric.
                if ( ! is_numeric( $min ) || ! is_numeric( $max ) ) {
                    $min = str_pad( wc_normalize_postcode( $min ), strlen( $destination_postcode ), '0' );
                    $max = str_pad( wc_normalize_postcode( $max ), strlen( $destination_postcode ), '0' );
                }

                if ( $destination_postcode >= $min && $destination_postcode <= $max ) {
                    return true;
                }
            }
        }
    }

    return $is_available;

}, 10, 3 );