iso-tracker bot should add product tag

[Elfy]

Currently the tracker bot adds iso-testing as a tag.

Would be better if it also added the product so that people can easily find reported bugs for their product.

Eg product-xubuntu for Xubuntu build reports or p-xubuntu to take less room on page.

[Pasi Lallinaho (knome)]

Furthermore, this would help people search and find information about which bugs affect multiple products without going digging deep in the ISO tracker history and bug lists (which are also painfully slow to load).

[Nicholas Skaggs (nskaggs)]

This should be a simple change; though I think bdmurrary would need to be invovled.