Improve channel endpoints

[fusion44]

Possible improvements:

• [ ] open-channel should take a push amount parameter
  • CLN: https://lightning.readthedocs.io/lightning-fundchannel.7.html
  • LND: https://lightning.engineering/api-docs/api/lnd/lightning/open-channel
  • Note, LND only supports sats for push amount, so we'll only support this everywhere
• [ ] list-channels should return the current Channel state (opening, normal, closing, etc)
  • Note, this requires research how to properly categorize the channel status across implementations
  • [ ] CLN-JRPC: https://lightning.readthedocs.io/lightning-listpeerchannels.7.html
  • [ ] CLN-GRPC: https://lightning.readthedocs.io/lightning-listpeerchannels.7.html
    • Note, must wait for next CLN which will include ListPeerChannels support to the gRPC endpoint
  • [ ] LND-GRPC: https://lightning.engineering/api-docs/api/lnd/lightning/list-channels
• [ ] list-channels should take an include "closed_channel" boolean parameter
• [ ] check if channel state changes are properly propagated through the SSE channel
• [ ] properly document the endpoint https://github.com/fusion44/blitz_api/blob/71ad84e70449daf2fa7cdcdb8a7ca4b4bac5acad/app/lightning/models.py#L392