feat(widgets): SelectionWidget POC

[ibgreen-openai]

Closes #

Background

This is just a proof of concept, it obviously cannot be landed in its current form

• A key requirement for infovis is the ability to offer selections in the UI.
• Widgets are a great way to surface this
• This depends on the editable-layers module and could be a widget exported from that module, once we publish the Widget base class.
  

Change List

[ibgreen-openai]

@georgioskarnas

[chrisgervang]

Yes, would love to see editable layers all packaged as deck widgets. Good to see the POC come together here, and agree we wouldn't want to bring any editable layers widgets into the core offering. Plus, it's be better for the ecosystem if we dogfood the custom widget class in our community libraries too.