Allow optional fields to accept empty values when creting/updating

[maxceem]

At the moment during creating or updating "TermsOfUse" records some optional fields cannot be set to an emtpy string "".

Can we allow setting optional fields to empty strings?

• url (string)
• text (string)
• legacyId(number) - as this is a numeric field, maybe we cannot allow to set it to an empty string in requests.