Campaigns data at organisation units of level 6

[tokland]

:pushpin: References

• Issue: Closes https://app.clickup.com/t/8693zh51d

:memo: Implementation

• [x] Wizard -> organisation Units -> selection only at level 6
• [x] Population (% at level 4 and 6, population at level 6)
• [x] Dashboards. Compare: dashboard-old.txt -> dashboard-new.txt
• [x] For actions "Edit" and "Set Target Population", if it's an old campaign it should show a snackbar error (as it cannot be edited).

Notes:

• Beware that MSF by default has a cache of 1 hour (System Settings -> Analytics -> Cache Strategy), so changes in Target Population won't be reflect after that time. For tests, I set it to "No cache"