Support template shortcode attributes

<?php

/**
 * [facetwp template="publications" project="housing"]
 *
 * Look for a "project" shortcode attribute. If one exists,
 * update the query to narrow results by that project
 */
add_filter( 'facetwp_query_args', function( $query_args, $class ) {
    foreach ( FWP()->display->shortcode_atts as $atts ) {
        if ( isset( $atts['template'] ) && isset( $atts['project'] ) ) {

            // Narrow results by the given project
            $query_args['tax_query'] = [
                [
                    'taxonomy' => 'project',
                    'field' => 'slug',
                    'terms' => $atts['project']
                ]
            ];
            break;
        }
    }
    return $query_args;
}, 10, 2 );