Dropdown: Allow empty string while not showing clear button

[Foxandxss]

Describe the bug

When setting [showClear] as true it will show up if the default "value" is an empty string. Initializing a form with empty strings is a recommended practice by the angular team.

Environment

Happens in both stackblitz and local project

Reproducer

https://stackblitz.com/edit/primeng-dropdown-demo-yz3mvk

Angular version

14.0.0

PrimeNG version

14.0.1

Build / Runtime

Angular CLI App

Language

TypeScript

Node version (for AoT issues node --version)

16.x.x

Browser(s)

All of them

Steps to reproduce the behavior

Check how the first example works as expected but the second one shows up the X even if the placeholder is showing up.

Expected behavior

The *ngIf for the icon should take in account empty strings as well.