Split out renderers into separate bundle (extension)

[DonJayamanne]

Why?

• Faster builds (CI, tests, etc)
  • No need to build this
• Smaller extension size
  • Renderer extension does not need to ship everytime
  • Once users have this, we don't need to download again
• Easier to manage
  • Can update out of band

Cost?

User experience

• Recommend renderers extension when working with .ipynb files vscode#132009
• Plotly output generated with 'notebook' renderer not shown after re-opening notebook #6404