[MM-58020] Improve error message of NotFound errors in store (#26870)

* Improve error message of NotFound errors in store

* update mmctl tests

server/cmd/mmctl/commands/channel_e2e_test.go

@@ -357,7 +357,7 @@ func (s *MmctlE2ETestSuite) TestDeleteChannelsCmd() {
 		_, err = s.th.App.GetChannel(s.th.Context, channel.Id)
 
 		s.Require().NotNil(err)
-		s.Require().Equal(fmt.Sprintf("GetChannel: Unable to find the existing channel., resource: Channel id: %s", channel.Id), err.Error())
+		s.Require().Equal(fmt.Sprintf("GetChannel: Unable to find the existing channel., resource \"Channel\" not found, id: %s", channel.Id), err.Error())
 	})
 
 	s.Run("Delete channel without permissions", func() {
@@ -401,7 +401,7 @@ func (s *MmctlE2ETestSuite) TestDeleteChannelsCmd() {
 
 		s.Require().Nil(channel)
 		s.Require().NotNil(err)
-		s.Require().Equal(fmt.Sprintf("GetChannel: Unable to find the existing channel., resource: Channel id: %s", notExistingChannelID), err.Error())
+		s.Require().Equal(fmt.Sprintf("GetChannel: Unable to find the existing channel., resource \"Channel\" not found, id: %s", notExistingChannelID), err.Error())
 	})
 }