UserStore migration (#15563)

* Migration completed

* Fix tests

* Fix tests

* Fix tests

* Suggestions

* Trigger CI

* Suggestions

* Merge with master

* Trigger CI

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>
Co-authored-by: Agniva De Sarker <agnivade@yahoo.co.in>

app/notification.go

@@ -26,7 +26,7 @@ func (a *App) SendNotifications(post *model.Post, team *model.Team, channel *mod
 	pchan := make(chan store.StoreResult, 1)
 	go func() {
 		props, err := a.Srv().Store.User().GetAllProfilesInChannel(channel.Id, true)
-		pchan <- store.StoreResult{Data: props, Err: err}
+		pchan <- store.StoreResult{Data: props, NErr: err}
 		close(pchan)
 	}()
 
@@ -58,8 +58,8 @@ func (a *App) SendNotifications(post *model.Post, team *model.Team, channel *mod
 	}
 
 	result := <-pchan
-	if result.Err != nil {
-		return nil, result.Err
+	if result.NErr != nil {
+		return nil, result.NErr
 	}
 	profileMap := result.Data.(map[string]*model.User)
 
@@ -504,9 +504,9 @@ func (a *App) filterOutOfChannelMentions(sender *model.User, post *model.Post, c
 	// Filter out inactive users and bots
 	allUsers := model.UserSlice(users).FilterByActive(true)
 	allUsers = allUsers.FilterWithoutBots()
-	allUsers, err = a.FilterUsersByVisible(sender, allUsers)
-	if err != nil {
-		return nil, nil, err
+	allUsers, appErr := a.FilterUsersByVisible(sender, allUsers)
+	if appErr != nil {
+		return nil, nil, appErr
 	}
 
 	if len(allUsers) == 0 {