Allow Sherlock input value to be controlled

[stdavis]

This would allow us to clear the input value from outside of the component. For example, I would like to clear the sherlock input when this clear button is clicked:

[steveoh]

I have vague memories of us talking about this during development and there was something about nesting it in a form and maybe using a reset button?

[stdavis]

Yes, I think that this would be a similar use case, no?

[stdavis]

This was closed via the context param introduced in #368