Primeng panel component on toggle show async data

[vipulk574]

Hi Team,

I have a requirement on primeng panel component toggle, once clicked on more button , data should be displayed dynamically using async.

```
<p-panel [toggleable]="toggle" [collapsed]="true">
<p-header> Entity Information </p-header>
<div class="row mb-4">
<div class="col-12">
<entity-information></entity-information>
</div>
</div>
</p-panel>
```

After clicking on panel, send an asynchronous request, get the data and send to entity information.
I've tried onClick event, but event triggers when clicked on completed header, instead, event should raise only when clicked on More button

I have also tried onBeforeToggle() but this function does not trigger. Could someone guide here.