REST request detection

Thank you for the great theme!

Please fix the detection of REST requests for the case with plain permalinks in \Kadence_Blocks_Frontend::is_rest. Discussion with the author of the code is here: https://gist.github.com/matzeeable/dfd82239f48c2fedef25141e48c8dc30#gistcomment-3870434

Instead of

		if ( ( defined( 'REST_REQUEST' ) && REST_REQUEST ) || ( isset( $_GET['rest_route'] ) && strpos( trim( $_GET['rest_route'], '\\/' ), $prefix, 0 ) === 0 ) ) {

you should use

		if ( ( defined( 'REST_REQUEST' ) && REST_REQUEST ) || ( isset( $_GET['rest_route'] ) ) ) {