Add Flask interview list endpoint

[rajeswari1301]

Replaced the redundant session query in interview_list.yml, which was executing 2–3 times per page load and now runs only once, tested it at 50 - 2375 saved sessions - and it was about about 2-3 times faster each time, getting better the bigger the list gets.

It supports all the same features - viewing, searching, renaming, deleting, copying, and paging through results and pulls its settings from the same config the old page already uses.

#1102

[nonprofittechy]

Minor nits. Biggest question to consider: should this definitely use HTML encoded into the file? An alternative is to use a traditional external HTML template. You'd need to load it in as a string though given that Docassemble only looks for Flask templates in one hardcoded folder.

[rajeswari1301]

Minor nits. Biggest question to consider: should this definitely use HTML encoded into the file? An alternative is to use a traditional external HTML template. You'd need to load it in as a string though given that Docassemble only looks for Flask templates in one hardcoded folder.

Thank you for the review! I fixed the CSS and package name.

Right now, the page wrapper currently uses a separate file. Registering the package's template folder directly with flask would be the fix rather than another workaround, but that would mean updating every link on the page and handling the check that stops this route from loading twice