Improve support for custom route/controller page implementations

[jesseleite]

Since we improved support for SEO meta on custom route/controller implementations with #303, we should look to improve support for custom route/controller implementations in SEO Pro's sitemap and reports features as well.

The problem is that SEO Pro doesn't know how to find custom content managed outside of Statamic. We have no idea if the user has defined custom Laravel routes, of if they're routing using something like Laravel Folio, or if they've got some kind of SPA setup for parts of their app, etc.

I'm thinking we can maybe create some helpers to allow the user to inject external content into the sitemap and report generator, but it would need some proper thought is all.

[jesseleite]

Though maybe the solution (for the sitemap anyway) is to...

[sattyframework]

Hey there, just wondered if there has been any support for custom routes yet? I have custom routes for e-commerce and checkout pages etc. At the moment I am not able to customize the SEO meta data for these routes.