fix(material/timepicker): ensure selected event fires after form control value is updated

[Mr-KRAMA]

Fix timepicker event ordering issue

Problem:
The timepicker was firing the selected event before updating the form control value. This made it impossible to access the updated form value in event handlers, which is inconsistent with how the datepicker works.

What was happening:

timepicker.selected.subscribe(event => {
  console.log('Event value:', event.value);        // ✅ New time
  console.log('Form control:', formControl.value); // ❌ Still old value
});

What happens now:

timepicker.selected.subscribe(event => {
  console.log('Event value:', event.value);        // ✅ New time  
  console.log('Form control:', formControl.value); // ✅ Updated value
});

Copy
typescript
Solution:

Modified the _selectValue method to emit the selected event after a microtask

This ensures the form control is updated before any event handlers run

Now behaves consistently with MatDatepicker

Testing:

Added test to verify form control value is available in selected event handler

All existing tests still pass

Fixes: #31950