In the screen showing templates also show repo url if public

As a user I'd like to see where is a given template coming from, to be able to compare best practices with public templates and debug my own templates.

Changes required would be to: `backend/graph-proxy/src/graphql/workflow_templates.rs` and `frontend/dashboard/src/routes/templateview.tsx`

Unclear - where is that initial information coming from?
At the moment `workflows.rs` has a Metadata struct

```rust

#[derive(Debug)]
pub(super) struct Metadata {
/// The name given to the workflow, unique within a given visit
name: String,
/// The visit the Workflow was run against
visit: Visit,
}

```

there seems to be an abscence of an similar metadata system for templates