Refactor find_route for precise channel balance info #397

Job	Run time
e2e test for 3-nodes-transfer --env test	4m 24s
e2e test for invoice-ops --env test	3m 50s
e2e test for open-use-close-a-channel --env test	3m 50s
e2e test for udt --env test	4m 3s
e2e test for reestablish --env test	3m 57s
e2e test for cross-chain-hub --env test	4m 5s
e2e test for router-pay --env test	4m 30s
e2e test for udt-router-pay --env test	4m 6s
e2e test for udt --env xudt-test	4m 9s
e2e test for 3-nodes-transfer --env test --env-var HASH_ALGORITHM=sha256	4m 22s
	41m 16s

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