Function event

event<TEventArgs extends Record<string, any>>(
    targetOrQuery: null | string | EventTarget,
    name: string,
    initialValue: undefined | TEventArgs,
    options?: Partial<EventOptions>,
): Reactive<TEventArgs> & { last(): TEventArgs }
Subscribes to an event, emitting data
Type Parameters
- TEventArgsextendsRecord<string, any>
Parameters
- targetOrQuery: null | string | EventTarget
  Event emitter, HTML element or string. If a string, it will be queryed as a selector.
- name: string
  Event name
- initialValue: undefined | TEventArgs
- options: Partial<EventOptions> = {}
  Options
Returns Reactive<TEventArgs> & { last(): TEventArgs }
Example: Print x,y position of mouse as it moves
```
const r = Rx.From.event(document, `pointermove`);
r.onValue(event => {
 const { x, y } = event;
});
```
If options.lazy is true (default: false), event will only be subscribed to when the stream itself has a subscriber.

options.debugFiring and options.debugLifecycle can be turned on to troubleshoot behaviour of the stream if necessary.