E2C: Add Public Preview banner (#90922)

* E2C: Add public preview message

* Read feedback URL from the settings

* Translate strings

* Add missing translation

* Add missing translation[2]

pkg/setting/setting_cloud_migration.go

@@ -23,6 +23,7 @@ type CloudMigrationSettings struct {
 	CreateTokenTimeout          time.Duration
 	DeleteTokenTimeout          time.Duration
 	TokenExpiresAfter           time.Duration
+	FeedbackURL                 string
 
 	IsDeveloperMode bool
 }
@@ -47,6 +48,7 @@ func (cfg *Cfg) readCloudMigrationSettings() {
 	cfg.CloudMigration.DeleteTokenTimeout = cloudMigration.Key("delete_token_timeout").MustDuration(5 * time.Second)
 	cfg.CloudMigration.TokenExpiresAfter = cloudMigration.Key("token_expires_after").MustDuration(7 * 24 * time.Hour)
 	cfg.CloudMigration.IsDeveloperMode = cloudMigration.Key("developer_mode").MustBool(false)
+	cfg.CloudMigration.FeedbackURL = cloudMigration.Key("feedback_url").MustString("")
 
 	if cfg.CloudMigration.SnapshotFolder == "" {
 		homeDir, _ := os.UserHomeDir()