The existing wallet_resendwallettransactions.py test only tests the
resendwallettransactions RPC. It does not test whether transactions are
actually rebroadcast, or whether the rebroadcast logic is called on a
timer.
This commit updates the test to not use the resendwallettransactions RPC and
test that transactions are rebroadcast on a timer.
This is a backport of Core PR15646