[Search v2.5] Remove special handling of policyID after navigation is merged

[luacmartins]

We need to remove this code once this navigation PR is merged.

@Kicu

[Kicu]

Thanks for the issue.

Some extra context

PolicyID (aka workspaceID) has a lot of special handling, as it comes from URLs but is also saved to workspaceContext. To avoid having multiple ways of accessing it, we try to access it from URL/route params whenever possible, and handle it on navigation actions.
In this specific case instead of overwriting workspace id, we can simply check if there is existing id during navigation and handle it.
That is already working in #49539

[Kicu]

also please assign me, so I won't forget about this 🙏

[luacmartins]

On hold

[luacmartins]

@Kicu the holding PR has been merged. Can we resume work on this one? This is lower priority than the current report projects though