Bootstrap copied BFF and local accounts with public Sendico contracts (#34)

backend/contracts/sendico/external/payment_state.yaml

@@ -0,0 +1,11 @@
+components:
+  schemas:
+    PaymentState:
+      type: string
+      enum:
+        - orchestration_state_unspecified
+        - orchestration_state_created
+        - orchestration_state_executing
+        - orchestration_state_needs_attention
+        - orchestration_state_settled
+        - orchestration_state_failed