Given the template
`<div (click)="doSomething($event)"></div>`
If you request references for the `$event`, the results include both `$event` and `(click)="doSomething($event)"`.
This happens because in the TCB, `$event` is passed to the `subscribe`/`addEventListener`
function as an argument. So when we ask typescript to give us the references, we
get the result from the usage in the subscribe body as well as the one passed in as an argument.
This commit adds an identifier to the `$event` parameter in the TCB so
that the result returned from `getReferencesAtPosition` can be
identified and filtered out.
fixes#40157
PR Close#40158
d466db8285