Adding some basic support for visual editing in VisualEditor. Currently it is nothing fancy, just the ability to recognize <tabber/> tags and a simple dialog with code editor to edit the Tabber code. It would be iterated upon in the future.
* Tab header bottom line is now full width instead of the width of the tabs. It aligns with the previous and current Tabber behavior on Fandom wikis
* Increase padding for tab buttons for bigger click area
* Appending __NOEDITSECTION__ to tab body seems to break the table markup (#12)
* Edit buttons still work for transcluded tabs so it should be visible
Closes#12
* Initial merge of the TabberTransclude extension from Ciencia
* Tab content can now be fetched from other pages on the wiki. The content is lazy-loaded when the tab is selected through a XHR request.
* Add a config option to disable setting URL hash on tab change
This replaces the current history context instead of adding a new entry. The
previous behavior was undesired when you switch tabs and you want to go back
to the previous page.
This catches every possible size change of the active tab panel contents:
* Window resize, will update also the offsetLeft property
* Inner size changes like a collapsible element being opened or closed
* And even tabber inside tabber, when the inner tabber is changed and they
have different sizes
ResizeObserver may not be supported by some old browsers, but that shouldn't
be too bad for them. If something looks displaced they can simply switch
tabs to force a resize.
