Backporting sidebar docking to Notepad++

[sdasda7777]

Description of the Issue | 需求描述

Hi, I saw your StackOverflow post where you showcased the sidebar docking you did for this project. I would love to have this feature in Notepad++, because there are many useful sidewindows to have that are often almost empty, so there is no point of switching between them instead of having them be split like you allow. Do you find it likely that you would be willing to backport this feature to Notepad++? If not, could you provide some overview to what would be necessary for me to do to do it myself? Do I understand correctly that the only required changes are in the DockingManager class, or are there other files/classes to keep in mind?