Describe the bug

When you run the editor, the panels remain closed until a request is sent to calculate their status (including resizing the window, dragging splitters to resize a panel, etc.). This is inconsistent with the editor's previous behavior and leads to a sudden change in the panels' status, which is seemingly without reason from the user's perspective.

To Reproduce

Steps to reproduce the behavior:

1. Open editor and open some panel (and resize them)
2. Close editor
3. Open editor again
4. Last panel status will not be loaded
5. Change editor window size or drag a splitter to see restored status

Expected behavior

Editor should restore status after startup.

Screenshots (Optional)

Nothing

Environmental Information (please complete the following information):

• OS: Windows 11
• Other system information: Nothing
• Version: 0.2-beta2

Additional context

This bug was probably introduced since #109, where the panels are loaded simultaneously.