Restore ability to reset pane split size by double clicking drag handle. (#3937)

Release notes
- Fixed double clicking on pane drag handle not resetting pane's split
size.
- Fixed pane group sizes not being serialized.
97aed8a4d7Piotr Osiewicz committed on 1/8/2024, 3:48:17 PM· committed by GitHubparent53564fb
1 file changedLine totals unavailable