Create table to store CPAN permissions

[preaction]

We need a way to keep track of which PAUSE accounts have permissions for which CPAN distributions. We will use this data to allow authorized accounts to perform actions on the CPAN Testers website.

We need to store the following information:

• The distribution name
• The PAUSE account ID

The new table should be called "UploadPerms" (all CPAN-based tables will be named "Upload*"). This data will be populated by a new backend process.