Realtime notifications with websockets

[franky47]

WIP: it works but there are conflicts when multiple clients (eg: tabs, windows, or devtools) are involved as everyone listens to notifications and races to consume incoming shared keys.

~This can be solved by using a SharedWorker where supported, and falling back to polling for older browsers.~ Edit: see comment below.

• [x] Auto-reconnect
• [x] Disconnect on document.visibility hidden (and reconnect on visible)
• [x] Use a single database listening connection for all WebSocket connections

[franky47]

Note: the use of a SharedWorker, not only being limited in browser compatibility, would require shipping the worker code along with the client library. Doing so independently of how the client is consumed (using a bundler or not, which one, etc), and while preserving strict Content Security Policies (not loading blobs or requiring the consuming application to allowlist an arbitrary URL) seems like a footgun.

Moreover, using a SharedWorker only allowed having a single WebSocket connection per "context", independent of the number of clients running in parallel (tabs/windows, devtools etc). The problematic of picking a main client to react to notifications (so they wouldn't end up in a data race to process incoming keys) would still have had to be solved, so let's solve it without involving SharedWorkers.

[github-actions[bot]]

:tada: This PR is included in version 1.0.0-beta.1 :tada:

The release is available on npm package (@beta dist-tag)

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[github-actions[bot]]

:tada: This PR is included in version 1.0.0-beta.1 :tada:

The release is available on npm package (@beta dist-tag)

Your semantic-release bot :package::rocket:

[github-actions[bot]]

:tada: This PR is included in version 1.0.0-beta.1 :tada:

The release is available on npm package (@beta dist-tag)

Your semantic-release bot :package::rocket: