This commit fixes a regression introduced in 8979adc where under certain conditions the groups syncing logic in Discourse Connect would try to add users to groups they're already members of and cause errors when users try to sign in using Discourse Connect.
Discourse Connect can be used to manage group memberships of users by including a `add_groups`, `remove_groups` or `groups` attribute in the Discourse Connect payload. However, additions/deletions of users from groups aren't logged to the groups logs (available at `/g/<group>/manage/logs`) which can cause confusions to admins they try to figure out when/how users were added or removed from a group. This commit makes Discourse Connect add entries to the groups logs when it makes changes to users' group memberships.
This commit resolves a bug where users are not auto approved based on
`SiteSetting.auto_approve_email_domains` when
`SiteSetting.must_approve_users` has been enabled.
This commit introduces a new site setting: `use_name_for_username_suggestions` (default true)
Admins can disable it if they want to stop using Name values when generating usernames for users. This can be useful if you want to keep real names private-by-default or, when used in conjunction with the `use_email_for_username_and_name_suggestions` setting, you would prefer to use email-based username suggestions.
