Function collectEventHandlers

collectEventHandlers(
content: string,
events: readonly string[],
): TemplateEventHandler[]
Event bindings named in events, in source order.

Parses a single Angular template with @angular/compiler and returns every event binding with a given name, split into the calls and assignments its handler expression makes and whether each of them reads $event.
Parameters
- content: string
  Raw template text.
- events: readonly string[]
  Event names (formError, valueChange for [(value)]).
Returns TemplateEventHandler[]
[] when the template cannot be parsed or the compiler is mocked.
Remarks
Pure function over template text, like inspectTemplate. Which element matches which directive, and which class method a call reaches, is resolved one level up in OutputFlowTracer. Element offsets use the same convention as inspectTemplate (offset of the tag name), so both results can be joined by position.

A two-way binding [(value)]="x" yields the event valueChange; its handler is reported as the assignment x = $event that Angular performs.
Example
```
const handlers = collectEventHandlers('<app-item (saved)="onSave($event)"></app-item>', ['saved']);
// [{ event: 'saved', tag: 'app-item', handler: 'onSave($event)',
//    steps: [{ kind: 'call', member: 'onSave', args: [{ index: 0, text: '$event', usesEvent: true }] }] }]
```