Allow scorecard at release level

Right now custom scorecards can be assigned only at the workspace lvl, which does not really allow for changing priorities and weightings. Worse, if we do change any fundamental portion of a scorecard, it will mass update everything in that workspace, thus we lose audit ability of the prior decision making that had happened within that workspace.

Since decision making and priorities will ALWAYS evolve over time, please consider scorecard assignment to also happen at the release level rather than just at the workspace level.