workflows: result templating

* Amends result rendering to use templates
  under the folder templates/workflows/results.

Signed-off-by: Georgios Papoutsakis <georgios.papoutsakis@cern.ch>
workflows: refextract templating

* fixes refextract task.

* Adds refextract templating.

Signed-off-by: Georgios Papoutsakis <georgios.papoutsakis@cern.ch>
workflows: documentaion for result templating

* Adds documentation for rendering the results.

Signed-off-by: Georgios Papoutsakis <georgios.papoutsakis@cern.ch>