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.
lntemp
lntest
This commit performs the takeover that `lntemp` is now promoted to be `lntest`, and the scaffolding is now removed as all the refactoring is finished!
itest
This commit moves all the test cases living in `itest` out of `lntest`, further making `lntest` an independent package for general testing.