When running the tests locally with a parallelism of 4 on an otherwise
busy system, RPC can take quite a wait to come up.
Change the timeout to 60 seconds just to be safe.
Github-Pull: #11091
Rebased-From: c1470a058f21bf98d83b9dc345c61626b87035cc
TestNode is a class responsible for all state related to a bitcoind node
under test. It stores local state, is responsible for tracking the
bitcoind process and delegates unrecognised messages to the RPC
connection.
This commit changes start_nodes and stop_nodes to start and stop the
bitcoind nodes in parallel, making test setup and teardown much faster.
Github-Pull: #10711
Rebased-From: 7897338918dac072e788b8ab2919d4559f311bef
