Media: Rename several attachment related parameters from $post_id to $attachment_id for clarity, and improve related

documentation.

See #41017


git-svn-id: https://develop.svn.wordpress.org/trunk@41288 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-image-editor.php

@@ -164,8 +164,8 @@ abstract class WP_Image_Editor {
 	 * @since 3.5.0
 	 * @abstract
 	 *
-	 * @param string $mime_type
-	 * @return bool|WP_Error
+	 * @param string $mime_type The mime type of the image.
+	 * @return bool|WP_Error True on success, WP_Error object or false on failure.
 	 */
 	abstract public function stream( $mime_type = null );