Fee reserve for lightning backends (#557)

* preparing fees

* fee_limit_msat

* await resp result

* clightning

* fix tests

* fix test

* add fee to test

* mypy

* invoice_status

* checking id fix

* fee reserve error message

* only for external payments

lnbits/wallets/opennode.py

@@ -77,7 +77,7 @@ class OpenNodeWallet(Wallet):
         payment_request = data["lightning_invoice"]["payreq"]
         return InvoiceResponse(True, checking_id, payment_request, None)
 
-    async def pay_invoice(self, bolt11: str) -> PaymentResponse:
+    async def pay_invoice(self, bolt11: str, fee_limit_msat: int) -> PaymentResponse:
         async with httpx.AsyncClient() as client:
             r = await client.post(
                 f"{self.endpoint}/v2/withdrawals",