In reply to Ahmad Awais.

@weston

1. Thanks, I will look for it. I assume this will be hard to hack from a widget but maybe my gut feeling is wrong here.

2. AFAIK the general attitude toward the customizer (and media library) in WPSE is "The code is unreadable, not going to bother to put the effort to understand it just to answer a question". And probably no one there has any reason to write anything for the customizer, people that build sites for client/workplace don't need it at all, only "for sell" theme developers need it.

As @rarst said on a comment here, wordpress is busy implementing features that might be interesting to users (and that is also in doubt), but have nothing in them for good developers.