[PLT-5864] Move teammate name display setting to the System Console (#6681)

* move teammate name display setting to the system console

* update all the likes of TeammateNameDisplay names

* fix gofmt error

* rebase and fix conflict

model/preference.go

@@ -17,13 +17,8 @@ const (
 	PREFERENCE_CATEGORY_ADVANCED_SETTINGS   = "advanced_settings"
 	PREFERENCE_CATEGORY_FLAGGED_POST        = "flagged_post"
 
-	PREFERENCE_CATEGORY_DISPLAY_SETTINGS   = "display_settings"
-	PREFERENCE_NAME_COLLAPSE_SETTING       = "collapse_previews"
-	PREFERENCE_NAME_DISPLAY_NAME_FORMAT    = "name_format"
-	PREFERENCE_VALUE_DISPLAY_NAME_NICKNAME = "nickname_full_name"
-	PREFERENCE_VALUE_DISPLAY_NAME_FULL     = "full_name"
-	PREFERENCE_VALUE_DISPLAY_NAME_USERNAME = "username"
-	PREFERENCE_DEFAULT_DISPLAY_NAME_FORMAT = PREFERENCE_VALUE_DISPLAY_NAME_USERNAME
+	PREFERENCE_CATEGORY_DISPLAY_SETTINGS = "display_settings"
+	PREFERENCE_NAME_COLLAPSE_SETTING     = "collapse_previews"
 
 	PREFERENCE_CATEGORY_THEME = "theme"
 	// the name for theme props is the team id