Since we don't have standby nodes anymore, we don't need to close the
channels when the test finishes. Previously we would do so to make sure
the standby nodes have a clean state for the next test case, which is no
longer relevant.
This commit removes the usage of the standby nodes and uses
`CreateSimpleNetwork` when applicable. Also introduces a helper method
`NewNodeWithCoins` to quickly start a node with funds.
To make this itest work reliably with multiple parallel SQL
transactions, we need to count both the settle and final HTLC
events. Otherwise, sometimes the final events from earlier
forwards are counted before the forward events from later
forwards, causing a miscount of the settle events. If we
expect both the settle and final event for each forward,
we don't miscount.
The route blinding itests are now updated so that recipient logic is
tested. The creation of a blinded route is also now done through the
AddInvoice API instead of manually.
Fixes the problem that inbound base fee and fee rate are overwritten
with 0 if they are not specified in PolicyUpdateRequest. This ensures
backward compatibility with older rpc clients that do not yet support
the inbound feature.
