Support post type admin column for hierarchical post type download

[codersantosh]

Support Post Type Admin Column for hierarchical Post Type

Currently, the plugin uses the action hook manage_posts_custom_column. This hook only supports the default case. No data will appear in the post type admin column if a developer changes the post type attribute to hierarchical. It can be solved either by changing the hook to manage_download_posts_custom_column or adding the hook add_action( 'manage_pages_custom_column', 'edd_render_download_columns', 10, 2 );. The first one is recommended.