feat(/form/ButtonInput): button that should be used along side inputs

Specifically for buttons needed that live on the same row as inputs. Not to be used for submit buttons! We should use our normal `/chrome/Button` for that.

app/components/form/ButtonInput.tsx

@@ -0,0 +1,6 @@
+import * as React from 'react'
+
+const ButtonInput: React.FunctionComponent<any> = ({ onClick, children }) =>
+  <button onClick={onClick} className='input button'>{children}</button>
+
+export default ButtonInput