URL helpers not including the relative url root [v5.5]

[orenyk]

Reported by BMEC:

... discovered that the Reports page isn't working properly. We can load the Reports page, but when we click on an equipment model to narrow the search, we get another Not Found page.

Verified on their instance, we should debug and figure this out.

[orenyk]

Not broken on release-v5.5, I'm wondering if it has something to do with the relative root again? EDIT: yup, the links don't include the relative root. Looking into why...

[orenyk]

Ok, figured it out. We need to configure the url_helpers module to have the same default options as action_mailer (i.e. host and relative root). This is technically blocked on #1434 since it relies on the appropriate use of script_name to set the relative root, so I'm going to reset this branch on there and we'll wait to open a PR.