Moving MFA service into shared libs (#16969)

* Moving MFA service into shared libs

* Fixing i18n extraction issue

* Fixing tests

app/authentication.go

@@ -8,7 +8,7 @@ import (
 	"strings"
 
 	"github.com/mattermost/mattermost-server/v5/model"
-	"github.com/mattermost/mattermost-server/v5/services/mfa"
+	"github.com/mattermost/mattermost-server/v5/shared/mfa"
 	"github.com/mattermost/mattermost-server/v5/utils"
 )
 

app/user.go

@@ -33,8 +33,8 @@ import (
 	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/model"
 	"github.com/mattermost/mattermost-server/v5/plugin"
-	"github.com/mattermost/mattermost-server/v5/services/mfa"
 	"github.com/mattermost/mattermost-server/v5/shared/i18n"
+	"github.com/mattermost/mattermost-server/v5/shared/mfa"
 	"github.com/mattermost/mattermost-server/v5/store"
 	"github.com/mattermost/mattermost-server/v5/utils/fileutils"
 )