ECOM-1502: Item Create and Update v8

Updated the item create and update services with the v8 WSDL. This adds an "Attribute Set"

Other improvements:

• Updated composer.lock file (it was out of sync) and added required PHP modules
• Removed references to deleted UnsupportedCurrencyException class
• Added strict type checking in strcascomp() output

@andrew-summers @weizhong-wang