[MM-19948] Set version on module file and internal paths (#13186)

* [MM-19948] Set version on module file and internal paths

* Fixes after merge

* Fix i18n checker error

app/plugin_shutdown_test.go

@@ -19,7 +19,7 @@ func TestPluginShutdownTest(t *testing.T) {
 			package main
 
 			import (
-				"github.com/mattermost/mattermost-server/plugin"
+				"github.com/mattermost/mattermost-server/v5/plugin"
 			)
 
 			type MyPlugin struct {
@@ -34,7 +34,7 @@ func TestPluginShutdownTest(t *testing.T) {
 			package main
 
 			import (
-				"github.com/mattermost/mattermost-server/plugin"
+				"github.com/mattermost/mattermost-server/v5/plugin"
 			)
 
 			type MyPlugin struct {