Finish CoCo v2 tests

[philsmart]

As Alex said:

Note that CoCo has two parts. SPs can assert the Data Protection Code of Conduct; IdPs can support the Code.

I think we've only covered the SP part. So we should also add the IdP part (Entity Category Support value)

[philsmart]

Actually, I think we have covered these but in different directory structures.

The IdP checks for check_coco_v2_support.xsl are in /xml/check_coco_v2_support. The SP checks are in xml/entity-categories/cocov2. I think, actually, what I should do here is move the IdP checks into the xml/entity-categories/cocov2 directory.