Add support for id:/do: links to dlg.usg.edu

Issue

We can go to

• https://dlg.galileo.usg.edu/id:record_id (note id:)
• https://dlg.galileo.usg.edu/do:record_id (note do:)

And also

• https://dlg.galileo.usg.edu/do-th:record_id
• https://dlg.galileo.usg.edu/do-pdf:record_id

With this issue, we want to be able to go to

• https://dlg.usg.edu/id:record_id
• https://dlg.usg.edu/do:record_id
• https://dlg.usg.edu/do-th:record_id
• https://dlg.usg.edu/do-pdf:record_id

(Until we can support do: links in dlg.usg.edu, a link like dlg.usg.edu/do:xyz redirects to dlg.galileo.usg.edu/do:xyz.)

Investigation

This page, https://discuss.rubyonrails.org/t/how-to-match-a-literal-colon-in-a-route/71717, has this snippet:

I did some digging on this, and I couldn’t find a way to make this work with a literal in the route itself.

Splatting works, though:

get ‘baz/*ark_tag/:id/bar’ => ‘welcome#index’, constraints: { ark_tag: ‘ark:’ }, as: :ark

will only match paths like “/baz/ark:/123/bar”.