Remove PFE redirect for project stats pages

[zwolf]

Removes stats from the regex that determines which project-level pages get redirected to PFE. These project stats pages will soon be served by FEM (fe-projects). Staging (frontend.preview) already does this by not having any PFE redirects.

Do not deploy this until the required FEM changes have been deployed, or else all project stats pages will become FEM 404s.

[goplayoutside3]

Corresponding PFE PR: zooniverse/Panoptes-Front-End#7474

[zwolf]

Added the explicit stats page PFE redirect to all of the private project directives to prevent them from displaying the new FEM stats page on deploy.

[lcjohnso]

Should we treat the special redirects differently than the private projects, or should we minimize PFE/FEM app switching behavior by keeping all PFE redirected projects using the current PFE stats page? I note that this decision is setting precedent for what we should do for recents, collections, users, etc. pages that are coming next.

I would vote to keep the PFE projects using all PFE pages, as I think it will be disorienting to flip back-and-forth between codebases while working on a project, but I defer to @goplayoutside3 as I suspect there may be other considerations at play.

[goplayoutside3]

I requested for Zach to keep all private projects' stats page on PFE, but everything else point to FEM. The reason is that I want all project pages that can use FEM to use FEM. PFE projects are now in the minority and they're only held back on that codebase for a specific classifier feature, or because they're private projects.

As we move more and more webpages from PFE to FEM, I want to use the FEM pages (recents and collections will be next), rather than continue to make exceptions for PFE projects. Also, FEM projects already bounce back and forth between the two frontends when navigating to Talk and back to the classifier. Overall, FEM webpages are a better, more accessible experience for users (at least that's the goal).

[lcjohnso]

All good -- as I said, I defer to Delilah, so good to go!