Add static parameters for CVSS attributes and their options

[fridan]

When creating input forms for CVSS vectors, it is tedious and badly maintainable to create all the necessary form items and their valid options by hand.

Instead it would be much easier to have a static method with which to retrieve all CVSS metrics (i.e. attack vector, attack complexity, scope, etc.) and their corresponding options. One could then iterate over them in order to generate the input fields as desired.

However there is no static methods to do so, forcing one to create a "dummy" CVSS vector, in order to iterate over all the various metrics.