Chips: Component is always disabled if not set to bind to a model

[timandella]

Describe the bug

In previous versions of PrimeNG (16.6.0 and earlier), it was possible to create a Chips component without explicitly binding to a model value (i.e. when reactive forms are used)

    <p-chips 
        separator="," 
        placeholder="Hint: a, b, c"></p-chips>

However, in 16.7.1 (and 16.7.0), this now results in the component being disabled, and the user unable to type anything in the control. It is only if you add the [(ngModel)] binding does the control become enabled.

In previous versions, omitting [(ngModel)] left the control as enabled, and the user could still type into the control

Environment

Windows

Reproducer

https://stackblitz.com/edit/7cfcg5?file=src%2Fapp%2Fdemo%2Fchips-comma-seperator-demo.html

Angular version

16.2.12

PrimeNG version

16.7.1

Build / Runtime

Angular CLI App

Language

TypeScript

Node version (for AoT issues node --version)

18.16.1

Browser(s)

Edge

Steps to reproduce the behavior

1. Set up a p-Chips element on an html page, without [(ngMode)] being specified
2. Run your app, and attempt to type into the control

Expected behavior

Control is enabled, and user can type in it to create new chips

[timandella]

Duplicate of #14062