Fix inherited member source not visible to subgroup members

What does this MR do and why?

In !144638 (merged), we introduced a bug due to which we started masking the parent group members from the subgroup members when the visibility of these groups were private.

To check if the member is from an ancestor we should check whether the current source contains the member's source ID in its traversal IDs but we were doing the opposite. The specs had a gap because we were only testing public groups there and this problem only occurred for private groups.

I have also added a feature spec to cover this case.

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Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Create a Parent group and its subgroup Child.
2. Add a new user User2 to Child.
3. Login using User2 and go to the members page of the Child.
4. On the master branch the Parent group member's source would be masked with Private but on this branch, it should be visible.

Related to #455884 (closed)

changed milestone to %17.0

added Category:Groups & Projects devopsdata stores grouptenant scale milestonep2 priority3 reproduced on GitLab.com sectioncore platform severity3 typebug workflowin review labels

assigned to @abdwdd

mentioned in issue #455884 (closed)

added backend label

Reviewer roulette

Category	Reviewer	Maintainer
backend	@j_lar (UTC+2, 3.5 hours behind author)	@brodock (UTC+1, 4.5 hours behind author)
test for spec/features/*	@j_lar (UTC+2, 3.5 hours behind author)	Maintainer review is optional for test for spec/features/*

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@j_lar could you please do the initial backend and test changes?

requested review from @j_lar

added 188 commits

• 6b7bd1ba...dbb78d77 - 187 commits from branch master
• 1e6e7d52 - Fix inherited member source not visible to subgroup members

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removed review request for @j_lar

added 1 commit

• 5a520497 - Use the new factory syntax to pass members to groups

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requested review from @brodock

resolved all threads

approved this merge request

added pipeline:mr-approved label

@brodock, thanks for approving this merge request.

This is the first time the merge request has been approved. To ensure we don't only run predictive pipelines, and we don't break master, a new pipeline will be started shortly.

Please wait for the pipeline to start before resolving this discussion and set auto-merge for the new pipeline. See merging a merge request for more details.

resolved all threads

@abdwdd LGTM! I've set it to MWPS