Add contrast/bias "adjust all images at once" to Plot Options

[Jdaviz-Triage-Bot]

Reporter: pllim

User wants to extend #1343 to include bias/contrast when selecting images from Plot Options to adjust them for all selected images at the same time.

Example workflow:

1. User select 2 images in Plot Options.
2. User set contrast and bias values in Plot Options.
3. User click button to apply those values two both images at the same time.

Unanswered questions:

1. What is the API equivalent way to achieve this?
2. Does this mean we no longer need the sliders affected by Contrast/bias sliders not as "snappy" as DS9 #1358 ?

🐱

---

DISCLAIMER: This issue was autocreated by the Jdaviz Issue Creation Bot on behalf of the reporter. If any information is incorrect, please contact Duy Nguyen