Shifting cursor (forward) when editing Markdown with emoji

When editing a markdown component with a specific emoji (which occupies two characters) - for example the start emoji which is by default on the markdown component, clicking on text places the cursor one character to the right and making editing confusing.

Expected results

Cursor stays at correct position

Actual results

Cursor jumps 1 step forward

Screenshots

It’s hard without video, but here are few screenshots (I can share video if needed). In this example I am trying to correct “payouss” to “payouts”

How to reproduce the bug

1. Go to Dashboard, Add Markdown with emoji (e.g. the start shape)
2. Try to edit a sentences (after the emoji) and see the cursor jumps around (deletes character forward, not correct one)

Environment

• superset version: master

Checklist

Make sure these boxes are checked before submitting your issue - thank you!

• I have checked the superset logs for python stacktraces and included it here as text if there are any.
• I have reproduced the issue with at least the latest released version of superset.
• I have checked the issue tracker for the same issue and I haven’t found one similar.

[junlincc]

@kkucharc 🙏

[zuzana-vej]

@junlincc FYI. I know there are other two open bugs for markdown https://github.com/apache/incubator-superset/issues/11304 and https://github.com/apache/incubator-superset/issues/11257 they are all different, just wanted to surface this as it relates to the same component.