Started basic playground for testing lexical as a new WYSIWYG editor.
Moved out tinymce to be under wysiwyg-tinymce instead so lexical is the
default, but TinyMce code remains.

Structured UI logical to be fairly standard and mostly covered via
a base class that handles context and core dom work.

Connected up to work with image form

With a bunch of default icons

Also added some basic context toolbar styling

Changed how the editor is loaded in, so it now creates its own DOM, and
content is passed via creation function, to be better self-contained.

Added more styling/layout for buttons and main content area

Also added extra lifecycle handling for decorators to things can be
properly cleaned up after node destruction.

Converted events service to TS as part of this.

Added new options that sits on the context, for things needed but not
for the core editor, which are defined out of the editor (drawio URL,
error message text, pageId etc...)

Also added smarter above/below positioning to respond if toolbar would
be off the bottom of the editor, and added hide/show when they'd go
outside editor scroll bounds.

Added scoll & page resize handling.
Added cropping/limiting to edit area.

Updated UI elements to handle new scenarios needed in more complex table
menu

Started building table cell form/actions

May show bad option label names on chrome/safari.
This was an easy first pass without loads of extra custom UI since we're
using native datalists.

To align with pre-existing use of alignment classes.

Added safeguarding/matching of source/target sizes to prevent broken
tables.

Changed from using a decorator to using a helper that watches for image
selections to then display a resize helper.
Also changes resizer to use a ghost and apply changes on end instead of
continuosly during resize.

- Updated selection change detection to be more accurate
- Added UI refresh for extra actions
- Fixed remove link deleting contents

- Improved node resizer positioning to be more accurate
- Fixed drop handling not running within editor margin space
- Made media dom update smarter to reduce reloads
- Fixed media alignment, broken due to added wrapper

- Cleaned up dropdown lists to look integrated
- Added icons for color picker clear and menu list items

Also updated media to be an inline element to align with old editor
behaviour.

Needed a custom implementation due to hardcoded defaults for Lexical
default indenting.

Added list nesting support to allow li > ul style nesting which lexical
didn't do by default.
Adds tab handling for inset/outset controls.
Will be a range of edge-case bugs to squash during testing.