fix(@desktop/sync): settings/display_name sync&backup handling

Part of #10389 issue.

src/app_service/service/profile/service.nim

@@ -27,7 +27,9 @@ proc newService*(events: EventEmitter, settingsService: settings_service.Service
   result.settingsService = settingsService
 
 proc init*(self: Service) =
-  discard
+  self.events.on(SIGNAL_DISPLAY_NAME_UPDATED) do(e:Args):
+    let args = SettingsTextValueArgs(e)
+    singletonInstance.userProfile.setDisplayName(args.value)
 
 proc storeIdentityImage*(self: Service, address: string, image: string, aX: int, aY: int, bX: int, bY: int): seq[Image] =
   try:
@@ -74,8 +76,5 @@ proc setDisplayName*(self: Service, displayName: string) =
     if(not self.settingsService.saveDisplayName(displayName)):
       error "could save display name to the settings"
       return
-    
-    singletonInstance.userProfile.setDisplayName(displayName)
-
   except Exception as e:
     error "error: ", procName="setDisplayName", errName = e.name, errDesription = e.msg

src/app_service/service/settings/service.nim

@@ -22,6 +22,7 @@ const DEFAULT_FLEET* = $Fleet.StatusProd
 
 # Signals:
 const SIGNAL_CURRENCY_UPDATED* = "currencyUpdated"
+const SIGNAL_DISPLAY_NAME_UPDATED* = "displayNameUpdated"
 const SIGNAL_CURRENT_USER_STATUS_UPDATED* = "currentUserStatusUpdated"
 
 logScope:
@@ -90,6 +91,9 @@ QtObject:
           if settingsField.name == KEY_CURRENCY:
             self.settings.currency = settingsField.value
             self.events.emit(SIGNAL_CURRENCY_UPDATED, SettingsTextValueArgs(value: settingsField.value))
+          if settingsField.name == KEY_DISPLAY_NAME:
+            self.settings.displayName = settingsField.value
+            self.events.emit(SIGNAL_DISPLAY_NAME_UPDATED, SettingsTextValueArgs(value: settingsField.value))
 
     self.initialized = true
 
@@ -185,6 +189,7 @@ QtObject:
   proc saveDisplayName*(self: Service, value: string): bool =
     if(self.saveSetting(KEY_DISPLAY_NAME, value)):
       self.settings.displayName = value
+      self.events.emit(SIGNAL_DISPLAY_NAME_UPDATED, SettingsTextValueArgs(value: self.settings.displayName))
       return true
     return false