goimports (#16640)

* format using `goimports -local github.com/mattermost/mattermost-server/v5 -w`

* added goimports lint check to .golangci.yml

* format using `goimports -local github.com/mattermost/mattermost-server/v5 -w` for a corner case

* make app-layers, *-mocks and store-layers for ci check

Co-authored-by: Mahmudul Haque <mahmudulhaque@protonmail.com>
Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

services/upgrader/errors.go

@@ -3,7 +3,9 @@
 
 package upgrader
 
-import "fmt"
+import (
+	"fmt"
+)
 
 // InvalidArch indicates that the current operating system or cpu architecture doesn't support upgrades
 type InvalidArch struct{}

services/upgrader/upgrader_linux_test.go

@@ -10,8 +10,9 @@ import (
 	"os"
 	"testing"
 
-	"github.com/mattermost/mattermost-server/v5/model"
 	"github.com/stretchr/testify/require"
+
+	"github.com/mattermost/mattermost-server/v5/model"
 )
 
 func TestCanIUpgradeToE0(t *testing.T) {