Organize backend into product executable and shared Go modules

backend/product/auth/request/login.go

@@ -0,0 +1,11 @@
+package srequest
+
+import sessionmodel "git.sendico.io/tech/sxchnge/product/sessions/model"
+
+import customermodel "git.sendico.io/tech/sxchnge/product/customers/model"
+
+type Login struct {
+	sessionmodel.SessionIdentifier `json:",inline"`
+	customermodel.LoginData        `json:"login"`
+	ClientSecret                   string `json:"clientSecret,omitempty"`
+}