Migrates Channel.GetByName to sync by default (#11187)

* Channel.GetByName and Channel.GetByNameIncludedDeleted sync by default

* Suggested changes

* Fix some vars shadowing

* Rename of vars inside goroutine

* Shadow variable corrected

app/command_msg.go

@@ -64,8 +64,8 @@ func (me *msgProvider) DoCommand(a *App, args *model.CommandArgs, message string
 	channelName := model.GetDMNameFromIds(args.UserId, userProfile.Id)
 
 	targetChannelId := ""
-	if channel := <-a.Srv.Store.Channel().GetByName(args.TeamId, channelName, true); channel.Err != nil {
-		if channel.Err.Id == "store.sql_channel.get_by_name.missing.app_error" {
+	if channel, channelErr := a.Srv.Store.Channel().GetByName(args.TeamId, channelName, true); channelErr != nil {
+		if channelErr.Id == "store.sql_channel.get_by_name.missing.app_error" {
 			if !a.SessionHasPermissionTo(args.Session, model.PERMISSION_CREATE_DIRECT_CHANNEL) {
 				return &model.CommandResponse{Text: args.T("api.command_msg.permission.app_error"), ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL}
 			}
@@ -77,11 +77,10 @@ func (me *msgProvider) DoCommand(a *App, args *model.CommandArgs, message string
 				targetChannelId = directChannel.Id
 			}
 		} else {
-			mlog.Error(channel.Err.Error())
+			mlog.Error(channelErr.Error())
 			return &model.CommandResponse{Text: args.T("api.command_msg.dm_fail.app_error"), ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL}
 		}
 	} else {
-		channel := channel.Data.(*model.Channel)
 		targetChannelId = channel.Id
 	}