Global Envvars need unique service entries

[mmattel]

With recent changes in the storage-user service, we have the situation that there are two envvars that use the same global variant, see OCIS_CACHE_STORE.

Because of this situation, the service is now listed twice for the same global envvar.

To solve this, the helper should report only uniqe occurences of services for the same global envvar.

@kobergj @dragonchaser

[dragonchaser]

Probably solvable in a simple way when #6028 introduces the needed mapping.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 10 days if no further activity occurs. Thank you for your contributions.

[mmattel]

keep open

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 10 days if no further activity occurs. Thank you for your contributions.

[mmattel]

keep open

[dragonchaser]

depends on #7105 otherwise the major release will come before we have finished it and will result in lots of tedious tasks (again like in 3.x.x to 4.0.0)

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 10 days if no further activity occurs. Thank you for your contributions.