Unicode::UCD: Remove access to some legacy-only properties

Unicode::UCD: Remove access to some legacy-only properties

Five files are currently being kept around only because they existed
before Unicode::UCD gave access to the properties they define, and some
application programs may rely on their presence, and format.  More
compact files have supplanted the use of these files by the Perl core.

Mistakenly, Unicode::UCD gave access to these files via the made-up
property names that they are referred to by in mktables.  This was
undocumented.  This commit removes this access.