Use absint for per-page param validation (#2563)

* Revert "Fix Products by Category JSON response error (#2551)"

This reverts commit 4ba1bbd.

* Fix Products by Category JSON response error

Author: Aljullu

src/StoreApi/Routes/AbstractTermsRoute.php

@@ -41,7 +41,7 @@ public function get_collection_params() {
 			'type'              => 'integer',
 			'minimum'           => 0,
 			'maximum'           => 100,
-			'sanitize_callback' => [ $this, 'get_intval' ],
+			'sanitize_callback' => 'absint',
 			'validate_callback' => 'rest_validate_request_arg',
 		);
 
@@ -156,14 +156,4 @@ protected function get_term_count( $taxonomy, $args ) {
 		unset( $count_args['number'], $count_args['offset'] );
 		return (int) wp_count_terms( $taxonomy, $count_args );
 	}
-
-	/**
-	 * Wrapper of the `intval` function that only accepts one parameter.
-	 *
-	 * @param mixed $value Value to convert to an int.
-	 * @return int
-	 */
-	public function get_intval( $value ) {
-		return intval( $value );
-	}
 }