Use unique ID for list URL path

List names are being used in the URL path to find lists, but since they can be renamed, it would be better to refer to them by their unique ID.

We should aim for a URL path like `/list/12345/PL_Pax6_Targets`, and ignore the name and only use the list ID when doing the lookup. This way we get the persistence of the list ID, while still retaining the readability of displaying a name.

It would probably be a good idea to also fix #365 when working on this (replacing `im-obj-id`, aka. internal id's used in `[:assets :lists mine-ns]`, with the persistent backend IDs).

Note that we can't implement this before we get unique list IDs on the backend: https://github.com/intermine/intermine/issues/2034

First verify that backend issue #2034 provides unique list IDs, then trace the current list URL path and name-based lookup. Check related issue #365 for the internal-ID replacement. Done means URLs retain a readable name but resolve using only the persistent list ID, with the related ID handling updated if included.

Written by the indexing model from the issue text.