Orders List Table doesn't show the subscription custom columns when HPOS is enabled

[mattallan]

Describe the bug

On stores with HPOS enabled, the Orders List table no longer shows the custom "Subscription Relationship" columns:

In our WC_Subscriptions_Order class we are hooking onto manage_edit-shop_order_columns and manage_shop_order_posts_custom_column hooks to add these custom columns, but these only work in non-HPOS environments.

For HPOS we need to use the following hooks:

• manage_woocommerce_page_wc-orders_columns
• manage_woocommerce_page_wc-orders_custom_column

To Reproduce

1. Enable HPOS
2. Purchase a subscription product and process a renewal
3. Visit the WooCommerce > Orders table and note that there's no columns for subscription relationships

Expected behavior

Actual behavior

Product impact

• [ ] Does this issue affect WooCommerce Subscriptions? yes/no/tbc, add issue ref
• [ ] Does this issue affect WooCommerce Payments? yes/no/tbc, add issue ref

Additional context

[EjayhanFernandes]

Initially reported here: 6532020-zen