copy-construct maEnhancedProtection in ScTableProtectionImpl

Change-Id: Ia1f7415b853f9e5ac585f89cbc938c2464c33fe5
write enhanced protection to .xls BIFF8 0x0868 Feat records

We now have a roundtrip of the EnhancedProtection feature.

Change-Id: Ib13b4d23a10dd51d9328de872e076bf58ee3127d