Problem:
Whitespace at the beginning and end of labels, descriptions, aliases and the Schema text are unnecessary. We already remove it for labels/descriptions/aliases on Items and Properties and a number of fields on Lexemes. The whitespace at the very beginning and end of a label, description, each of the aliases and the Schema text should be trimmed when saving.

BDD
GIVEN a Schema
WHEN entering a label, description, alias or Schema text with a whitespace at the beginning or end
AND then saving the input
THEN the whitespace is discarded before storing

Acceptance criteria:

• any number of spaces at the beginning or end of the label, description, aliases or Schema text of a Schema is discarded before saving
• any whitespace in places other than the beginning or end is kept as-is