Add Policy Violations Column to Projects Page

### Current Behavior:
The Projects page offers the following columns:

* Project Name
* Version
* Last BOM Import
* BOM Format
* Risk Score
* Active
* Vulnerabilities

ie, no display of policy violations

### Proposed Behavior:
Add a sortable "Policy Violations" column to the page. This will make it easy to perform tasks such as:
* Sort by risk and check for low policy violaton count... which may be an indication that policies are incorrectly configured.
* Sort by policy violation count to see the worst offending projects. When policies are "mature" then these projects should perhaps be focused on first.

Note that a simple count of total violations would include License and Operability Risk... so maybe a bit more nuance might be needed.

Start at the Projects page implementation and inspect how the existing Risk Score and Vulnerabilities columns obtain values and support sorting. Determine which policy violations count, including how License and Operability Risk are handled, then verify that the displayed counts and sorting work for representative projects.

Written by the indexing model from the issue text.