Provide toggle context to children

[melohagan]

I realised there was no way for the toggle to pass its state to the Budibase app. I'm creating this PR for you because I had to figure out how to use the context myself 😅 - I'll follow up with some docs tomorrow hopefully.

So the context provides bindings to the children. You then need to add the Provider component to expose those bindings to the children, which are indicated by the generic <slot />.

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There's a couple of other things you could have done instead. One is as a form component, another would be to add the onClick event:

{
    "type": "event",
    "label": "On Click",
    "key": "onClick"
  }

I think the context provider works well for something like a toggle.

[YuanZhang98]

Thanks for contributing this, that looks awesome. 🥰