[engine.io] `_query` should be optional

[BlueskyFR]

Hi!

Following the Nuxt tutorial (https://socket.io/how-to/use-with-nuxt) and as a follow-up on this ( #5323 ) unanswered discussion, I think the following line/variable _query should be made optional:

socket.io/packages/engine.io/lib/transport.ts

Line 16 in 07cbe15

_query: Record<string, string>;

Since handleRequest() in:

socket.io/packages/engine.io/lib/server.ts

Line 758 in 07cbe15

this.prepare(req);

calls prepare(), which sets the _query field even if it doesn't exist yet:

socket.io/packages/engine.io/lib/server.ts

Lines 734 to 740 in 07cbe15

	private prepare(req: EngineRequest) {
	// try to leverage pre-existing `req._query` (e.g: from connect)
	if (!req._query) {
	const url = new URL(req.url, "https://socket.io");
	req._query = Object.fromEntries(url.searchParams.entries());
	}
	}

And my editor currently complains about the types mismatch after completing the above mentionned tutorial:

Thanks in advance!

[BlueskyFR]

Also, shouldn't a wrapper/official Nuxt module be made instead of making users go through the definition of a custom Nitro plugin?
Many repos tried and are now outdated, but making it official would certainly help for sure