feat: add invoice and alternative_componen management functionality

internal/models/responses/alternative_component_response.go

@@ -0,0 +1,14 @@
+package responses
+
+type CreateAlternativeComponentResponse struct {
+	ID int64 `json:"id"`
+}
+
+type UpdateAlternativeComponentResponse struct {
+	ID                     int64  `json:"id"`
+	InvoiceConfigItemID    int64  `json:"invoiceConfigItemId"`
+	AlternativeComponentID int64  `json:"alternativeComponentId"`
+	ConversionRatio        string `json:"conversionRatio"`
+	Priority               int32  `json:"priority"`
+	Note                   string `json:"note"`
+}