Add a ghost variant to the input component in Estuary

[salieflewis]

This may exist as a ghost variant to whatever our default input component looks like. But the idea here is that the component doesn't initially look like an input component until it is clicked/being focused on.

[salieflewis]

In reality what we'll do is add a variant to the shadcn base Input component.

[salieflewis]

Resolved in #211 although further changes will still need to be made.