fix clearing a form field

• this.updateFetched(this.props.fetched && !this.props.fetching); caused the SchemaForm to re-render every 300ms, this prevented a form field from being cleared as the values were re-rendered into the input elements.
• In addition, the mechanism to clear a field was debounce for 2.5s, but this didnt update the current form data, meaning double backspace would give you back a single character
• Thirdly allow the enter key on textarea
• explicitly allow submit on enter for certain forms

If we allow enter to submit the form does it queue or not the scan? Related to #116 (closed)