This is to enable the detection of tx confirmation within Cashtab via the use of Chronik websockets. This diff is specific to Cashtab Web and Extension. A separate diff will be made for Cashtab Components as this diff matures.

Upon successful broadcast of a tx, the websocket subscribes to the hash160 of the active p2pkh address in cashtab to listen for the very first confirmation that matches the txid, at which point the tx will be deemed as completed.

Timing for the first confirmation will obviously vary for now but this'll become fairly consistent after pre-consensus takes it down to seconds. The websocket reconnects every 2 mins by default, which is ok for now given the average 10 min block times but we can revisit this after post/pre-consensus.

Getting this in will support other features such as live tracking of multi-sig signings for eCash DAOs, Point of Sale functionalities for merchants, the full metamask experience via Cashtab Components...etc.

The updates to webpack.config.js is to resolve webpack 5 conflicts which causes 'Module not found' errors with fs and assert.

Dependencies: Chronik client, assert

1. npm i && npm i assert && npm start
2. Send a 1 to 1 XEC transaction, note the websocket initialization (AddedToMemPool msg) in the console and verify confirmation notification in UI when the explorer shows at least one confirmation for this tx.
3. Verify via console the websocket is closed upon detection of the first confirmation (i.e. no further reconnection attempts).
4. Repeat 2 & 3 for a 1 to many XEC transaction
5. Repeat 2 & 3 for a send eToken transaction
6. Repeat 2 & 3 for a burn eToken transaction
7. Verify cross browser compatibility
8. Verify in extension plugin mode