fix(OrganisationUnitTree): deduplicate orgunit roots

[Birkbjo]

Implements LIBS-702

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Description

In OrganisationUnitTree component, you can pass roots that are descendants of other roots, e.g. if you pass <OrganisationUnitTree roots=[OrgUnitA, OrgUnitB, OrgUnitC] /> where OrgUnitB is a descendant of OrgUnitA and where OrgUnitC is a descendant of OrgUnitA, then you presumably want to display only OrgUnitA as a root (e.g. the deduplicated root).

This PR implements a function deduplicateOrgUnitRoots that will check the levels of the units, and only return the true "minimal roots" - and ignore rendering input IDs as roots, if another root contains it.

Know issues

• This will still send a request for each input orgunit. But will filter the "nested" units before rendering, once we know the "level".
  • Sidenote: I really think we should update how the roots are fetched. We do not need a separate request for each unit - those can be grabbed by using an in-filter. It quite wasteful currently.
    • This would be simple in it self, but would probably require a lot of work to update tests - and some apps' test might break if we were to do that.

Checklist

• API docs are generated
• Tests were added
• Storybook demos were added

All points above should be relevant for feature PRs. For bugfixes, some points might not be relevant. In that case, just check them anyway to signal the work is done.

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[dhis2-bot]

🚀 Deployed on https://pr-1625--dhis2-ui.netlify.app

[Birkbjo]

Note that we could use the "path" instead of level here - because path consists of the ids, and every id has the same length. But it's more semantically correct to use the level, even if I had to add another field to the request.