[feature]: First click in timeline view should not set dates

Is there an existing issue for this?

• I have searched the existing issues

Summary

When in the timeline layout, clicking an item pulls up a modal on the right hand side.

It's a common behavior amongst our users to click "off the modal" when editing a story to get "back to the timeline", as this is just a typical UX expectation.

However, when doing this, because of the [+] that sets the dates for an item that just happens to be under the mouse, even though the background is grayed out. This is a common problem in other scenarios as well, as an errant click sets dates, and people don't even realize they've put an item in the backlog onto the timeline until later.

This [+] UI could use additional consideration, and at least at a minimum:
• Delay 1.5s before showing the plus
• Don't show the plus if a modal is displayed

Why should this be worked on?

Improve UX.