fix: TEs layer not showing all relationships when source and target a…

…re of same type (#3281)

* fix: in fetchTEIs: use program instead of TE type
fix: in isIndexInstance:
- support bidirectional relationships
- store target TE ids
fix: in getDataWithRelationships:
- support all scenario TE type/program provided or not in source/target
- build targetInstances from relationships

* fix: update teiRelationshipsParser logic and add test

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Co-authored-by: Jen Jones Arnesen <[email protected]>