[chronik] Electrum: Add ws and wss transports
Summary: This is part of the protocol but not used by ElectrumABC.
Test Plan:
./test/functional/test_runner.py chronik_electrum_basic
Testing WSS:
./src/bitcoind -regtest -chronik -chronikelectrumbind=127.0.0.1:50001:y -chronikelectrumcert=/path/to/server.crt -chronikelectrumprivkey=/path/to/server.key
In a python console:
>>> import json
>>> import ssl
>>> import websocket
>>> ws = websocket.WebSocket(sslopt={"cert_reqs": ssl.CERT_NONE})
>>> ws.connect("wss://127.0.0.1:50001")
>>> ws.send(json.dumps({"jsonrpc": "2.0", "method": "server.features", "params": [], "id": 42}))
>>> print(ws.recv())Reviewers: #bitcoin_abc, PiRK
Reviewed By: #bitcoin_abc, PiRK
Differential Revision: https://reviews.bitcoinabc.org/D18304