If the monero wallet rpc has not already been downloaded we download the monero cli package and extract the wallet rpc. The unneeded files are cleaned up. The monero wallet rpc is started on a random port which is provided to the swap cli.
We added a fork of tokio-tar via a git subtree because we needed a tokio-tar version that was compatible with tokio 1.0. Remove this subtree in favor of a regular cargo dependency when this PR merges: https://github.com/vorot93/tokio-tar/pull/3.
The bitcoind wallet required the user to run a bitcoind node. It was replaced with a bdk wallet which allows the user to connect to an electrum instance hosted remotely. An electrum and bitcoind testcontainer were created to the test the bdk wallet. The electrum container reads the blockdata from the bitcoind testcontainer through a shared volume. bitcoind-harness was removed as bitcoind initialisation code was moved into test_utils. The bdk wallet differs from the bitcoind wallet in that it needs to be manually synced with an electrum node. We synchronise the wallet once upon initialisation to prevent a potentially long running blocking task from interrupting protocol execution. The electrum HTTP API was used to get the latest block height and the transaction block height as this functionality was not present in the bdk wallet API or it required the bdk wallet to be re-synced to get an up to date value.
