Fix double setting tag

Factored the default class handling into its own function.
Use `findIndex()` to locate default class.

- Ignore disturbed for both readable and writable
- Adds test to ensure previous protocol doesn't interrupt conversion.

Fix AbortSignal.any serialisation when re-validating Python.

Link events were not being emitted anywhere, only the type and support for
serializing it was implemented. It will not be available in the initial version,
but may be supported in the future if there is a use case for it.

This doesn't seem needed with the equivalent downstream code (correct outcome is
still reported when not setting it within EdgeworkerEventDispatcher), but it
feels safer to have it than to omit it.

These events were intended to be used with hibernatable web sockets, but since
there is a new customEvent and thus a new stream of tail events every time a web
socket resumes from hibernation, its information is best described using
HibernatableWebSocketEventInfo as part of the Onset event, which is already
implemented.

...to reduce logging volume while debugging.

sqlite: temporarily mark SQLITE_BUSY status as NOSENTRY to reduce logging volume while debugging