Monitors need an authenticated user when running checks

[PeteDarinzo]

There are cases when monitor checks require an authorized user or at least rely on the username getter from the BaseService.

[jskupsik]

+1 - I've encountered this need recently as well.

A neat way to do this would be to "assert an ad-hoc user context", ie something like:

asUser(email: '[email protected]', roles: ['HOIST_ADMIN', 'HOIST_ADMIN_READER']) {
    assert username == '[email protected]'
    assert user.hasRole('HOIST_ADMIN_READER')
    // ...
}

[lbwexler]

jakub -- clever idea -- seems like it could generally be useful for monitoring, if we needed to monitor mutliple things that only certain users could do. trying to think of other times where it would be usful.

Need to convince ourselves of the security of it. Certainly would not want it to be the "authUser" which I think should only arise via Authentication service.

A dedicated 'monitor' user seems perhaps easier to reason about