XProfile: Updating group order should purge 'xprofile_groups_inc_empty' cache

[r-a-y]

On the "Users > Profile Fields" admin page, create a bunch of profile groups.

Next, go to your "Profile > Edit" page to view the profile group tabs. Everything should be all good.

Now, go back to the "Users > Profile Fields" admin page, and rearrange the Profile Groups in a different order. Then, navigate back to "Profile > Edit" on the frontend. The profile group tabs are not showing the newer order.

The problem is we are not clearing the cache when a Profile Group is reordered.

01.patch fixes this and includes a unit test.

[r-a-y]

Forgot to mention that you need an object cache enabled to see the bug. The unit test should demonstrate the problem though.

[boonebgorges]

Good catch, r-a-y. Thanks!

[r-a-y]

In 8986:

XProfile: Purge profile group cache when profile groups are reordered.

Commit also includes a unit test.

Fixes #5860.