WIP: New melt flow (#622)

* `PaymentResult`

* ledger: rely on PaymentResult instead of paid flag. Double check for payments marked pending.

* `None` is `PENDING`

* make format

* reflected changes API tests where `PaymentStatus` is used + reflected changes in lnbits

* reflect changes in blink backend and tests

* fix lnbits get_payment_status

* remove paid flag

* fix mypy

* remove more paid flags

* fix strike mypy

* green

* shorten all state checks

* fix

* fix some tests

* gimme ✅

* fix............

* fix lnbits

* fix error

* lightning refactor

* add more regtest tests

* add tests for pending state and failure

* shorten checks

* use match case for startup check - and remember modified checking_id from pay_invoice

* fix strike pending return

* new tests?

* refactor startup routine into get_melt_quote

* test with purge

* refactor blink

* cleanup responses

* blink: return checking_id on failure

* fix lndgrpc try except

* add more testing for melt branches

* speed things up a bit

* remove comments

* remove comments

* block pending melt quotes

* remove comments

---------

Co-authored-by: lollerfirst <lollerfirst@gmail.com>

tests/test_mint_api.py

@@ -3,7 +3,7 @@ import httpx
 import pytest
 import pytest_asyncio
 
-from cashu.core.base import MeltQuoteState, MintQuoteState, ProofSpentState
+from cashu.core.base import MeltQuoteState, MintQuoteState
 from cashu.core.models import (
     GetInfoResponse,
     MintMethodSetting,
@@ -478,7 +478,7 @@ async def test_api_check_state(ledger: Ledger):
     response = PostCheckStateResponse.parse_obj(response.json())
     assert response
     assert len(response.states) == 2
-    assert response.states[0].state == ProofSpentState.unspent
+    assert response.states[0].state.unspent
 
 
 @pytest.mark.asyncio