Purchases: Users and sites purchases not loaded correctly

[scruffian]

When loading a site's purchases before a user's purchases, the collections aren't properly merged meaning that both appear in the list:

We need to ensure that they are properly merged together to prevent this happening.

[fabianapsimoes]

@scruffian when would this happen? Do we have steps to reproduce?

[scruffian]

This situation doesn't seem to happen any more; the bug has mutated. It now works like this:

If I have an account with purchases for more than one site, when I visit /purchases directly I see this:

However if I next navigate to /settings/general/:site, for one of the sites with purchases, (you have to navigate, not go there directly) and then return to /purchases, I see this:

Now if I visit /settings/general/:site, directly and then navigate to to /purchases I see this:

The issue is that on both /purchases and /settings/general/:site we fetch a list of purchases, but they aren't the same list, so we need to handle these cases better.

[kriskarkoski]

I recently encountered this on a user's site (multiple domain subs instead of one, no cancel option on the main domain card) and noticed that once auto renewal was disabled from SA the issue went away. Re-enabling auto renew did not allow the issue to happen again so disable auto renew once "fixed" whatever was causing them to be split and have the cancel option missing.