[Location Hierarchy] Update the hierarchy creation process to retrieve child locations using lineage location tags.

[dubdabasoduba]

Contexta

• OpenSRP currently builds a location hierarchy by recursively traversing the Location.partOf property in the Location resources.
• This ticket aims to enhance the functionality by enabling the retrieval of child locations using the Location.meta.tags present in the Location resources.
• These location tags are generated as described in [Location Hierarchy] Enable storing ancestor tags on all locations. #110.

Implementation

• Update the process for fetching child locations during location hierarchy creation to use lineage location tags instead of recursively traversing the hierarchy via the Location.partOf property.
• Backward compatibility

Acceptance Criteria

• Child locations in the hierarchy are retrieved using lineage location tags.

[pld]

Let's use a feature flag to control this, so we can support older versions of the data that don't have hierarchies in them

[pld]

We can remove this after we get the new version in production and it's working good, and all the data is migrated