Rename require_password_to_approve
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This setting is no longer just for passwords, but also being used to ask the user to re-authenticate with SAML if they have it setup, so we need to make the naming reflect a general re-authentication.
Rename merge_request_approval_setting for password `require_password_to_approve` =\> `require_reauthentication_to_approve`
- [x] rename DB
- [x] Take https://gitlab.com/gitlab-org/gitlab/-/merge_requests/52032#default-values+s into account
- [x] update API for MergeRequestApprovalSettings to accept `require_reauthentication_to_approve` besides previous parameter.
- [x] Make sure the value is mirrored between both columns in the interim until we fully remove `require_password_to_approve` to keep them in sync.
- [ ] add migration to sync previous setting to `require_reauthentication_to_approve`
* [ ] migration for `project_settings` => Rework https://gitlab.com/gitlab-org/gitlab/-/merge_requests/155652 to a batched background migration
* [x] migration for `group_merge_request_approval_settings`
- [ ] ~~rename occurrences in frontend~~ =\> https://gitlab.com/gitlab-org/gitlab/-/issues/468866+s
- [ ] r~~ename occurrences in backend~~ =\> https://gitlab.com/gitlab-org/gitlab/-/issues/468866+s
- [x] update documentation
Refs: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/130204
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