Auth: Add anonymous users view and stats (#78685)

* Add anonymous stats and user table

- anonymous users users page
- add feature toggle `anonymousAccess`
- remove check for enterprise for `Device-Id` header in request
- add anonusers/device count to stats

* promise all, review comments

* make use of promise all settled

* refactoring: devices instead of users

* review comments, moved countdevices to httpserver

* fakeAnonService for tests and generate openapi spec

* do not commit openapi3 and api-merged

* add openapi

* Apply suggestions from code review

Co-authored-by: Alex Khomenko <Clarity-89@users.noreply.github.com>

* formatin

* precise anon devices to avoid confusion

---------

Co-authored-by: Alex Khomenko <Clarity-89@users.noreply.github.com>
Co-authored-by: jguer <me@jguer.space>

pkg/services/anonymous/anonimpl/client_test.go

@@ -49,7 +49,7 @@ func TestAnonymous_Authenticate(t *testing.T) {
 				cfg:               tt.cfg,
 				log:               log.NewNopLogger(),
 				orgService:        &orgtest.FakeOrgService{ExpectedOrg: tt.org, ExpectedError: tt.err},
-				anonDeviceService: &anontest.FakeAnonymousSessionService{},
+				anonDeviceService: anontest.NewFakeService(),
 			}
 
 			identity, err := c.Authenticate(context.Background(), &authn.Request{})