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>

cashu/core/models.py

@@ -213,7 +213,7 @@ class PostMeltQuoteResponse(BaseModel):
     fee_reserve: int  # input fee reserve
     paid: Optional[
         bool
-    ]  # whether the request has been paid # DEPRECATED as per NUT PR #136
+    ] = None  # whether the request has been paid # DEPRECATED as per NUT PR #136
     state: Optional[str]  # state of the quote
     expiry: Optional[int]  # expiry of the quote
     payment_preimage: Optional[str] = None  # payment preimage
@@ -224,6 +224,8 @@ class PostMeltQuoteResponse(BaseModel):
         to_dict = melt_quote.dict()
         # turn state into string
         to_dict["state"] = melt_quote.state.value
+        # add deprecated "paid" field
+        to_dict["paid"] = melt_quote.paid
         return PostMeltQuoteResponse.parse_obj(to_dict)