Add standard checks to the assigning of a country name

Add standard checks to the assigning of a country name

Add check to ensure a country by that name does not exist.
Ensure the length is not too long.  Note this is a change
behaviour for edit and change commands which used to silently
truncate long names.  Enforce that a country name can not have
control characters in it.  Ensure that a country name is not
blank or just spaces.