CR-131 and CR-50: Fix crash on oxcfxics on syncing FAI messages

When Only Specified Properties is set at `RopSyncConfigure`.

This avoids leading to crash on getting FAI properties in sync operations
when OnlySpecificProperties and FAI synchronisation flags are set.

This also implements IgnoreSpecifiedOnFAI flag according
to the [MS-OXCFXICS] page 113 specification:

   > If the OnlySpecifiedProperties flag is set and the IgnoreSpecifiedOnFAI flag is not set, the
   server writes only the specified properties and subobjects for all messages to the FastTransfer
   stream.
   If the OnlySpecifiedProperties flag is set and the IgnoreSpecifiedOnFAI flag is also set, the
   server MUST write only the specified properties and subobjects for all non-FAI messages to the
   FastTransfer stream. For FAI messages, the server MUST write all properties and subobjects to the
   FastTransfer stream.
Ah, this was already there in the old code. Fair 'nough.