Fix duplicate teams+experiences in user list api

[fm3]

Our query suffered from Left Join Fanout effect, leading to duplicates. This is resolved by using subqueries with WITH, as described here.
Also, an inner join with user_team_roles would lead to users being omitted altogether in case they have no team memberships.
Also, the users_ view should be used for the join, in order to skip deleted users. Unfortunately, using the view means all selected fields need to occur in the GROUP BY clause (that shortcut is not available for views)

URL of deployed dev instance (used for testing):

• https://fixuserlistduplicates.webknossos.xyz

Steps to test:

• Assign multiple experiences and team roles to a user
• /api/users should include their teams and experiences only once each.

Issues:

• fixes SQL Errors (Duplicate Key) on Experience domain edits #7644
• follow-up: Audit all queries containing LEFT JOIN for fanout effect causing duplicates #7647

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• Updated changelog