rendering throws if the page contains a toggle

[Pierre Carion]

The fix is to ignore for now 'toggle' blocks
A toggle block is defined like that:

{ role: 'reader',
   value:
    { id: '91629d65-f538-4f2e-9c7b-c40a8320861c',
      version: 42,
      type: 'toggle',
      properties: { title: [ [ 'toggle list?' ] ] },
      content:
       [ 'dd651889-8ba1-48ef-a26b-d69d484243b0',
          'c70c17b9-8d74-4c66-8000-c89a50f1088a' ],

but.. the block ids are not part of the blocks returned with the page.