[feat] add click callback for textPane

[shouldsee]

Description

Motivation and Context

Would like to trigger event in business py script upon clicking a text pane. Needs a rebase before merge. (only merge 7cbb7c4)

How Has This Been Tested?

no test

Screenshots (if appropriate):

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.

[shouldsee]

Ah sorry I was not very good at separating commits. I think 7cbb7c4 is pretty much enough for the front end. Just needs to add test to make sure backend correctly process this event.