This commit is a backport of https://github.com/odoo/enterprise/commit/245759ef82250a8eb32f38853e5c5f6aac841823 and https://github.com/odoo/enterprise/commit/a35d64133cc3c598c66fcadc2310b0118a678424.

## Issue
When renewing a subscription, the tags and followers are not copied from the original subscription to the new one.

## Steps to reproduce
1. Install *Subscriptions* (`sale_subscription`)
2. Create a confirm a subscription S
    - Any *Customer*
    - Any *Recurring Plan*
    - Any Product
    - In the *Other Info* tab, add a tag T
3. There should be two followers on the subscription S: the creator of the subscription, and the customer. If it is not the case, add at least one follower.
3. Create and confirm an invoice for subscription S
4. Back on the subscription S, click *Renew*
5. **The tag T is missing on the new subscription. Also, the followers were not copied from subscription S.**

## Cause & Fix

### Tags
In `SaleOrder._prepare_upsell_renew_order_values`, tags are not part of the `values` generated when renewing a subscription:

https://github.com/odoo/enterprise/blob/a650fb74fd79965a6f0e441e61d8977c599057e6/sale_subscription/models/sale_order.py#L1149-L1171

They were added by https://github.com/odoo/enterprise/commit/245759ef82250a8eb32f38853e5c5f6aac841823:

https://github.com/odoo/enterprise/blob/245759ef82250a8eb32f38853e5c5f6aac841823/sale_subscription/models/sale_order.py#L1173-L1175

### Followers
Similarly to the tags, followers were not added/subscribed to the subscription when generating the renewed subscription. This was fixed by https://github.com/odoo/enterprise/commit/a35d64133cc3c598c66fcadc2310b0118a678424, by creating and calling the `_subscribe_followers_to_new_order(order)` after creating the new subscription (`order`):

https://github.com/odoo/enterprise/blob/a35d64133cc3c598c66fcadc2310b0118a678424/sale_subscription/models/sale_order.py#L956-L958

https://github.com/odoo/enterprise/blob/a35d64133cc3c598c66fcadc2310b0118a678424/sale_subscription/models/sale_order.py#L2147-L2157

opw-5478071

Forward-Port-Of: odoo/enterprise#107230