lnrouter+lnworker: use liquidity hints

Adds liquidity hints for the sending capabilities of routing channels in the
graph. The channel blacklist is incorporated into liquidity hints.
Liquidity hints are updated when a payment fails with a temporary
channel failure or when it succeeds. Liquidity hints are used to give a
penalty in the _edge_cost heuristics used by the pathfinding algorithm.
The base penalty in (_edge_cost) is removed because it is now part of the
liquidity penalty. We don't return early from get_distances, as we want
to explore all channels.

electrum/network.py

@@ -62,7 +62,6 @@ from .version import PROTOCOL_VERSION
 from .simple_config import SimpleConfig
 from .i18n import _
 from .logging import get_logger, Logger
-from .lnutil import ChannelBlackList
 
 if TYPE_CHECKING:
     from .channel_db import ChannelDB
@@ -350,7 +349,6 @@ class Network(Logger, NetworkRetryManager[ServerAddr]):
         self._has_ever_managed_to_connect_to_server = False
 
         # lightning network
-        self.channel_blacklist = ChannelBlackList()
         if self.config.get('run_watchtower', False):
             from . import lnwatcher
             self.local_watchtower = lnwatcher.WatchTower(self)