Frame for displaying pinned tabs

@Mino260806 sure, this looks fine and can help navigation if the user pinned a lot of tabs.

And, for such optional panels, using some kind of dockable framework will be great (ModernDocking looks quite active), but this will be a huge task to do 😭

And, for such optional panels, using some kind of dockable framework will be great (ModernDocking looks quite active), but this will be a huge task to do 😭

I think this deserves to be a seperate PR. ModernDocking seems to also support split panels and tabbed panes.
So if we start using ModernDocking, it's better to migrate other components like code split view, jnode tabbed pane, etc to preserve consistency of the codebase and the gui look.

So I'll implement this feature temporarily using normal swing framework, and then it shouldn't be difficult to migrate it to ModernDocking alongside other gui components.

Almost done, some small tweaks and then PR is ready

@skylot let me know what you think!

@Mino260806 thank you! Great work 👍