Removing all FakeApp usages (#14174)

* Removing some other fake apps

* More FakeApp removed

* Removing entirely FakeApp

* Fixing some tests

* Fixing get Cluster id from get plugin status

* Fixing failing tests

* Fixing tests

* Fixing test initialization for web

* Fixing InitServer for server tests

* Fixing InitServer for server tests

* Reverting go.sum and go.mod

* Removing unneded HTMLTemplates function in App layer

* Moving back some functions to its old place to easy the review

* Moving back some functions to its old place to easy the review

* Using the last struct2interface version

* Generating store layers

* Fixing merge problems

* Addressing PR comments

* Small fix

* Fixing app tests build

* Fixing tests

* fixing tests

* Fix tests

* Fixing tests

* Fixing tests

* Fixing tests

* Moving license to server struct

* Adding some fixes to the test compilation

* Fixing cluster and some jobs initialization

* Fixing some license tests compilation problems

* Fixing recursive cache invalidation

* Regenerating app layers

* Fix test compilation

Co-authored-by: mattermod <mattermod@users.noreply.github.com>

app/user.go

@@ -191,9 +191,13 @@ func (a *App) IsUserSignUpAllowed() *model.AppError {
 	return nil
 }
 
-func (a *App) IsFirstUserAccount() bool {
-	if a.SessionCacheLength() == 0 {
-		count, err := a.Srv().Store.User().Count(model.UserCountOptions{IncludeDeleted: true})
+func (s *Server) IsFirstUserAccount() bool {
+	cachedSessions, err := s.sessionCache.Len()
+	if err != nil {
+		return false
+	}
+	if cachedSessions == 0 {
+		count, err := s.Store.User().Count(model.UserCountOptions{IncludeDeleted: true})
 		if err != nil {
 			mlog.Error("There was a error fetching if first user account", mlog.Err(err))
 			return false
@@ -206,6 +210,10 @@ func (a *App) IsFirstUserAccount() bool {
 	return false
 }
 
+func (a *App) IsFirstUserAccount() bool {
+	return a.Srv().IsFirstUserAccount()
+}
+
 // CreateUser creates a user and sets several fields of the returned User struct to
 // their zero values.
 func (a *App) CreateUser(user *model.User) (*model.User, *model.AppError) {