Remove Roles and UserRole tables

[ryanrath]

Description

We have been running for some time without actually utilizing these tables and as such
it should be safe to remove them. These changes will make sure that the tables are not
created / referenced in ETL actions as well as making sure that they are removed in
existing installations when an upgrade is performed.

Motivation and Context

An error was encountered on Prod when a User that had existed when we were using the Roles / UserRoles tables and as such had records in the UserRoles table was deleted. Since UserRoles had a FK to Users.id the User removal failed and the Internal Dashboard / Existing Users Tab was put into an unusable state as the user in question still existed in the User table but did not have any ACL's associated with it, which broke the UI code, and thus the interface.

Tests performed

All automated tests for upgrade / fresh install

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Code Cleanup

Checklist:

• My code follows the code style of this project as found in the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.