refactor(templater): Format decimals according to locale

models/certificate.go

@@ -37,4 +37,5 @@ type CertificateTemplateOptions struct {
 	EventName      string                `json:"event_name"`
 	Footer         string                `json:"footer"`
 	CurrencySymbol string                `json:"currency_symbol"`
+	Locale         string                `json:"locale"`
 }