MM-50347 Make desktop app landing page optional (#28421)

* fix: Make desktop app landing page optional

* Update i18n strings

* Fix linting and unit test

---------

Co-authored-by: Kiran <kiran@krinati.co>

server/public/model/config.go

@@ -387,6 +387,7 @@ type ServiceSettings struct {
 	EnableAPITeamDeletion                             *bool
 	EnableAPITriggerAdminNotifications                *bool
 	EnableAPIUserDeletion                             *bool
+	EnableDesktopLandingPage                          *bool
 	ExperimentalEnableHardenedMode                    *bool `access:"experimental_features"`
 	ExperimentalStrictCSRFEnforcement                 *bool `access:"experimental_features,write_restrictable,cloud_restrictable"`
 	EnableEmailInvitations                            *bool `access:"authentication_signup"`
@@ -825,6 +826,10 @@ func (s *ServiceSettings) SetDefaults(isUpdate bool) {
 		s.EnableBotAccountCreation = NewPointer(false)
 	}
 
+	if s.EnableDesktopLandingPage == nil {
+		s.EnableDesktopLandingPage = NewPointer(true)
+	}
+
 	if s.EnableSVGs == nil {
 		if isUpdate {
 			s.EnableSVGs = NewPointer(true)