Contained Content Item Routing

[deanmarcussen]

Fixes #2688

WIP

Introduces a Container Routing Part which provides routes for contained items, like taxonomies, and bag items.

Includes compromises to achieve this, however is achievable, and can provide clean routes, e.g. for a taxonomy /categories/travel/some-place

Will demo and see what everyone thinks

Currently there's also a lot of code duplication between autoroute and container route, so would look to resolve some of that later

@jtkech For info I abstracted the transformer rather than using multiple transformers, as the catchall pattern could only be used by one transformer, or if a catchall, and a not quite catchall transformer used, a third not quite catchall transformer couldn't be used.

[mawendel]

Great Dean, this was exactly what i was looking for a little while back!

[jtkech]

@deanmarcussen

Okay makes sense, so a kind of composite transformer, let me know if you have any problem ;)

[deanmarcussen]

Okay makes sense, so a kind of composite transformer, let me know if you have any problem ;)

Yes, kind of @jtkech - not totally, because a transformer would check better for ambiguous matches, where these providers rely on check for duplicates before adding entries.

I chose not to make it async, because our IAutorouteEntries pattern, doesn't need it, and performance... but let me know if you think it would be better to be async by default (as the transformer's do use ValueTask)

[deanmarcussen]

Replaced by #5665 as was easier than dealing with the merge conflicts.

Leaving this branch intact, but pr closed