Add scope critical_notifications to login client

[#78946108] https://www.pivotaltracker.com/story/show/78946108

Signed-off-by: Rob Gallagher <rgallagher@pivotallabs.com>
Update tests suites for more test coverage for ScimGroupEndpoints
Remove file, UserIdInjector, not used anywhere in the code base
Fix example MySQL database configuration

Signed-off-by: Rob Gallagher <rgallagher@pivotallabs.com>

[Skip CI]
Implement an error handler for errors that are uncaught during Spring security filters, as those are not handled by endpoints
Throw correct exception
Remove code that is never exercised
Increase test coverage, ScimGroupEndpoints