Enable row height and content mode settings for Tree (#9540)
* Enable row height setting for Tree
* Add content mode for captions
* Align expander element by default to top
The content mode allows use of preformatted and
HTML captions that bring value to row height
Fixes #9411
Reorganize packages of connectors introduced in 8.1 (#9340)
* Move Tree and TreeGrid connectors to different package
* Move grid renderers to correct package
Only renderers introduced in 8.1 have been moved for
backwards compatibility.
This patch introduces a Tree component, implemented as a Composite
using TreeGrid. As initial version of the component, some functionality
of the old Tree component has been left out for now.
Partly addresses #8617