Feedback for non-normalized typed entry fields

[bwanders]

If a field in data entry has a type hint and the type can not normalize the given value then the user should receive feedback about this.

For example, the Start [date] field correctly normalizes 2016-02-18, but can not normalize 2016/02/18. Both represent the same dates to a human. Without normalisation the latter represents a flat string to Strata.

This break in user expectation is currently silently ignored. Possible options for improvement are:

• Highlighting all fields that did not normalize,
• showing notifications of field normalisation during preview.