Prevent initial fetch in `onUpdate`

[Tyler-Petrov]

When calling the onUpdate method of the ConvexClient I'd like to see an options parameter where I could specify lazy as true. When lazy is true the initial data fetch wouldn't happen.

When options: {lazy: true} is speficied here...

convex-js/src/browser/simple_client.ts

Lines 185 to 190 in ab02ff0

	onUpdate<Query extends FunctionReference<"query">>(
	query: Query,
	args: FunctionArgs<Query>,
	callback: (result: FunctionReturnType<Query>) => unknown,
	onError?: (e: Error) => unknown,
	): Unsubscribe<Query["_returnType"]> {

...this this code doesn't run

convex-js/src/browser/simple_client.ts

Lines 214 to 225 in ab02ff0

	// If the callback is registered for a query with a result immediately available
	// schedule a fake transition to call the callback soon instead of waiting for
	// a new server update (which could take seconds or days).
	if (
	this.queryResultReady(queryToken) &&
	this.callNewListenersWithCurrentValuesTimer === undefined
	) {
	this.callNewListenersWithCurrentValuesTimer = setTimeout(
	() => this.callNewListenersWithCurrentValues(),
	0,
	);
	}