PICARD-561: keep collections ordered like on the website

Collections submenu is now completely rebuilt on updates, though i don't think it will cause any issue.
Fix Refresh action

```
AttributeError: 'CollectionMenu' object has no attribute 'refresh_action'
```
Sort collections list in a similar way than on the website

Not perfect, but simple enough.
Merge pull request #244 from zas/order_collections

PICARD-561: keep collections ordered like on the website