Minor updates to the Package installation and extraction as part of PR #417
Fixing issue in MacroRepository which was causing a test to fail.

Changing the alias of a macro property didn't alias work, so added a fallback to the Id of the property in the cases where the Alias wouldn't work.
This Can_Find_Targetted_Migrations test needed a valid database to pass. This update ensures that the database is created with the old version 4.8 db schema.