Truncate input value on blur

[guyfedwards]

On blurring of the input, truncate the value to a sensible width and add an ellipsis to indicate 'more text'.

The input would need to calculate this 'sensible width' based on its width and the font-size (can probably be assumed).

Based on feedback and discussion with @bia in #317:

Right, when the text input field is in focus, there should be no character limit (or maybe like one of 256 characters, the max for email) and even partial letters would be displayed as the person selects and navigates the field.

When they click outside of the input field, we limit the text displayed to 28 characters, or 25 plus ellipsis.