By applying the urlencode filter whenever repo.name is templated into a URL, this would fix https://pagure.io/fedora-infrastructure/issue/12613, which contains a detailed description of the problem and symptoms.

Basically, a + character in a URL query string can be interpreted as a space, and without this PR, URLs may contain unescaped + characters in query strings for projects like https://src.fedoraproject.org/rpms/libsigc++20 that have + in the repo name. We are then at the mercy of other systems; in Fedora, it seems like something did change quite recently, triggering https://pagure.io/fedora-infrastructure/issue/12613.

While a strict fix for the observed issue would just urlencode repo names that are templated into query strings, we really should urlencode repo names wherever they are templated into query strings in order to avoid other unforeseen issues, and doing so should cause no harm, so that’s what this PR does.