Probe to blinded path

[ellemouton]

todo:

• convert Invalid blinding error to successful probe attempt
• itest for EstimateRoutingFee to blinded path invoice

[github-actions]

Pull reviewers stats

Stats of the last 30 days for lnd:

	User	Total reviews	Time to review	Total comments

[coveralls]

Pull Request Test Coverage Report for Build 11178137042

Details

• 12 of 49 (24.49%) changed or added relevant lines in 3 files are covered.
• 64 unchanged lines in 13 files lost coverage.
• Overall coverage increased (+0.02%) to 58.829%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
lnrpc/routerrpc/router.pb.go	0	5	0.0%
lnrpc/routerrpc/router_server.go	1	8	12.5%
lnrpc/routerrpc/router_backend.go	11	36	30.56%

Files with Coverage Reduction	New Missed Lines	%
queue/gc_queue.go	2	96.51%
blockcache/blockcache.go	2	86.36%
htlcswitch/link.go	2	80.37%
watchtower/wtdb/migration4/range_index.go	3	50.9%
contractcourt/breach_resolver.go	3	88.33%
watchtower/wtdb/range_index.go	3	96.12%
watchtower/wtdb/migration8/range_index.go	3	13.18%
lnrpc/wtclientrpc/wtclient.go	3	62.5%
chainntnfs/btcdnotify/btcd.go	4	83.07%
sweep/sweeper.go	5	89.44%

Totals
Change from base Build 11178121894:	0.02%
Covered Lines:	130767
Relevant Lines:	222284

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💛 - Coveralls