[IMPORT URLS] Simulate Webentity creation rule should take the matching rule with the longest prefix

[boogheta]

In some cases it does the opposite, for instance when we have

- facebook.com: path-1
- facebook.com/pages: path-2
- facebook.com/groups: path-2
- facebook.com/people: path-2

and we try to import the following batch

https://www.facebook.com/dude
https://www.facebook.com/dude/
https://www.facebook.com/people/dude
https://www.facebook.com/people/dude
https://www.facebook.com/groups/dude
https://www.facebook.com/groups/dude/
https://www.facebook.com/pages/dude
https://www.facebook.com/pages/dude/
https://www.facebook.com/post/dude
https://www.facebook.com/post/dude/

It should propose all WEs completely to the right except for the last 2 but it only proposes path-1 for all

This may come from calls to get_potential_prefix in the traph? cc @Yomguithereal

[Yomguithereal]

The traph is geared to returning the longest prefix but maybe there is something not working as intended.

[boogheta]

Well in fact, the traph wasn't the culprit, it was due to www variations of default creation rules not being automatically created