Remove obsolete validation when importing stores from OnPrem (RTC-25000)

Stores are imported properly when: post code is empty, city is empty, close date is before opening date, local store number is 0, phone is not valid for given country code.
Phone is validated to be a number. Spaces are removed from number to make it valid. Country calling code prefix is added.
Store groups with type 'Common' and 'Default' are skipped instead of failing.