Organization scoped paths - ambiguous paths

We are introducing a new top level scoping system using o for Organizations. Nearly all paths will be scoped by Organization under the o scope such as https://gitlab.com/o/my-org/my-group/my-project/-/issues. Further details of the scoping are available at https://handbook.gitlab.com/handbook/engineering/architecture/design-documents/organization/decisions/004_path_scope/

This issue is specifically to scope paths that are ambiguous and which result in the Organization Context calculation not being able to use the current path or header. We will target all Routable paths in another issue because they're a special case.

These kinds of pages may also require follow up changes such as query filtering. Identifying this type of work is very valuable so please add follow up issues to the &18089 epic and include links in the list below.

A starting point...

Feature	MR	Follow up issues
projects new/create	!197425 (merged)	#556339 (closed)
groups new/create	!197572 (merged)
projects index
groups index
sign in - per type
sign out
personal homepage		&19202
dashboards ...