This also adds two new keyboard shortcuts:
Save project hex: (Windows) Ctrl+Shift+S; (Mac) Cmd+Shift+S
Send to micro:bit: (Windows) Ctrl+Shift+E; (Mac) Cmd+Shift+E

Use a dialog to show WebUSB errors with clearer action for the user.

Updates Pyright to a version with the changes from microbit-foundation/pyright#35 and conditionally hides the new messages depending on the connected device.

A new setting can hide the messages. The setting can be flipped from a CodeMirror diagnostic action.

See https://microbit-global.monday.com/boards/1125389526/views/244984/pulses/1434825789

This is experimental at this point and is part of investigating PWA
support for the micro:bit Python Editor.

Notable behaviours:
- Fallback to English when changing language offline (when the selected language assets aren’t cached).
- Shows image placeholders for uncached images when offline.
- The app will automatically trigger a page reload when it detects the service worker has been updated. The service worker is updated when any of the build assets are updated.

There are two levels of feature gating:
- It's only enabled for microbit-foundation builds to avoid others shipping it accidentally. You can change FEATURE_PWA in the build to change this. We're open to a better system of build-time feature flags if there's interest (at least allowing existing env vars to override would make sense).
- There's a client side feature flag. You have to set this via `localStorage.setItem("flags", "pwa")` for now if you want to test an actual PWA install. We'll default that flag on to release to the beta after building more confidence internally.

Known issues:
- The app name is too long for the iOS home screen and is truncated by eliding the space between micro:bit and Python then a .... It works fine when you open it. We'll discuss whether it's reasonable to address this or live with it. It doesn't seem to be related to the colon in micro:bit and the user can customise the app name.

This is something of a compromise and requires a header.

This should amount no meaningful change but is a useful preliminary to extracting the device code for reuse.

Incorporates the only meaningful file from https://github.com/DerZade/typescript-event-target/ (with licence details) to save on the dependency.

* Translation sync & add pl as preview
* Update for Pyright chunk name fix

Remove it locally as the SW code bails in that scenario anyway.

sendRequest isn't an async function and it can synchronously throw errors
so we need something to prevent reentrant updates in the error case.

Otherwise though we don't needed it if we move more work into the state.

I've also calculated line/column ASAP - I'm not sure this is necessary but it
feels obviously correct / straightforward which is a win in this code.

Closes #1199