role page in UI breaks when a group member no longer exists

[t4niwa]

The role page in Athenz UI breaks when a role has a group member that no longer exists. The UI calls getGroup for each group member in Promise.all(), and a single 404 causes the whole page to fail.

This can happen when a domain template containing groups is deleted via deleteDomainTemplate. The normal deleteGroup API runs groupMemberConsistencyCheck and would reject the deletion, but the template deletion path does not.

Steps to reproduce

1. Apply a domain template that creates a group (e.g., tmpltest:group.mygroup)
2. Add that group as a member to a role in another domain (e.g., victim:role.myrole)
3. Delete the domain template via deleteDomainTemplate
4. Open victim:role.myrole members page in UI
5. Page fails: getGroup: Group not found: 'tmpltest:group.mygroup'

What should happen

The role page should still load. The deleted group member can remain in the list without expanded details.

[t4niwa]

Closing this as the two PRs have been merged.