* Allow tabs to wrap to multi-line

* Address feedback

* Add hidden space after last tab

* some polish for multi-line wrap css class

* some more polish

* Address feedback

* some adjustments to move forward

* add clarifying comment to tabs layout

* Fix editor container height

* WIP - overflowing tabs

* fix getPreferredHeight()

* Fix editor drop target for multi-line tabs

* Add comments and remove !important

* fix dnd offset

* Rework layout algorithm

* Make layout return a Dimension

* WIP - set maxDimensions

* Layout multi-line tabs synchronously

* make sure dimensions are always defined and passed down to where needed

* Rework group.relayout and store lastComputedHeight

* fix breadcrumbs causing editor to disappear

* consolidate css rules

* rename setting

* simplify classes

* streamline relayout

* wrapTabs => experimentalWrapTabs

* tweak layout

* Limit wrapped tabs to 3 rows

* Only use flex-grow for `tabSizing: fit`

* fix scrollbar reveal to work properly

* tabs - get rid of sync layout

* WIP: Move editor actions to the bottom right

* some tweaks

* introduce css variable for margin-right trick

* add border to separate tabs when wrapping

* 💄

* rename setting

* 💄 layout method
Co-authored-by: NBenjamin Pasero <benjpas@microsoft.com>