Is your feature request related to a problem? Please describe.
I'm trying to implement a UI using floating panels. One requirement is for the panels' positions to persist when the page is refreshed. Currently this is not possible because there are no event listeners available for when a floating panel is moved or closed.

Describe the solution you'd like
Expose event listeners for when a floating panel is moved or closed.

Describe alternatives you've considered
Currently I'm using the SerializedDockview to get panel position, and I've hidden the close button by using a custom tab component. I'm using external controls to add/remove panels, and before that occurs I store the panel's position in local storage. This works fine when hiding/showing the panels with my external controls, but moving a panel and then refreshing the page results in losing the latest position data.