Cleanup/extend error handling

[C-Otto]

The error handling in logic.py is ugly and incomplete. I'd like the list of handled errors to be more complete (see https://github.com/lightningnetwork/lightning-rfc/blob/master/04-onion-routing.md). Furthermore, it might make sense to ignore nodes instead of (unidirectional) channels. As a bonus, I'd appreciate someone else checking the current implementation. I'm not sure if the correct edge is ignored (off by one?).

[C-Otto]

It seems the hop/channel/edge BEFORE the failing one is ignored. From lnd debug logs (reporting to mission control is being developed in lightningnetwork/lnd#3221):

2019-06-25 20:09:56.270 [ERR] CRTR: Attempt to send payment ddc4a0f2daa328f69521f269853396fde28ae52d08fdaa181909129ace0eeb5b failed: TemporaryChannelFailure(update=(*lnwire.ChannelUpdate)(0xc00c892000)({
 Signature: (lnwire.Sig) (len=64 cap=64) {
  00000000  6c f5 eb ad ec 0d a6 ce  d6 aa fa 9a 63 79 83 40  |l...........cy.@|
  00000010  7e 7b 66 d0 34 a6 2e 46  c8 ce f3 74 5e 08 a2 8e  |~{f.4..F...t^...|
  00000020  51 07 2d a3 fd 4d 23 2e  04 ff 32 59 0d cb 09 a0  |Q.-..M#...2Y....|
  00000030  fd b9 7a d4 7c ae fe de  29 fd 68 69 b8 55 a6 3a  |..z.|...).hi.U.:|
 },
 ChainHash: (chainhash.Hash) (len=32 cap=32) 000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f,
 ShortChannelID: (lnwire.ShortChannelID) 581425:2314:0,
 Timestamp: (uint32) 1561457374,
 MessageFlags: (lnwire.ChanUpdateMsgFlags) 00000001,
 ChannelFlags: (lnwire.ChanUpdateChanFlags) 00000000,
 TimeLockDelta: (uint16) 40,
 HtlcMinimumMsat: (lnwire.MilliSatoshi) 1000 mSAT,
 BaseFee: (uint32) 1000,
 FeeRate: (uint32) 1,
 HtlcMaximumMsat: (lnwire.MilliSatoshi) 9900000000 mSAT,
 ExtraOpaqueData: ([]uint8) <nil>
})
)
2019-06-25 20:09:56.271 [DBG] CRTR: Reporting channel 639283548331311104 failure to Mission Control

From the script output:

Trying route #1
634892098831843329 -> 639283548331311104 -> 639297841954357249
Temporary channel failure, ignoring channel 634892098831843329

[C-Otto]

Good enough.