feat(Impact Analysis): Support impact analysis to check all downstreams of given entity

[dexter-mh-lee]

Support impact analysis!!

To make this happen, we added the following functionalities:

1. Standardize how we fetch lineage.

Traditionally, we enable relationships via the Relationship annotation in the PDL definition. This defines source - type - destination edge. However, some of these edges show up as an edge on the lineage view and some do not. Making things more complicated, for some, the direction of edge flips in the lineage graph i.e. Consumes vs Produces edge.
We added a lineage registry to keep track of all of this information in the Relationship annotation. You can add "isLineage" to denote that this edge is a lineage edge.

2. Add multi-hop capability on elasticsearch based graph service

Added BFS logic to elasticsearch graph service to support the impact analysis feature. We have some timeouts in place to make sure we don't traverse indefinitely for extremely large graphs.
This feature is not yet available for neo4j and dgraph based implementations. Only single hops are supported for these backends, and the impact analysis button will not show up if the underlying implementation is not elasticsearch.

3. Add LineageSearchService, which first fetches the downstream of a given entity and adds that as a filter in the search request to support search across the downstream entities (i.e. query, filter, and all)

4. Add capability to download search result as CSV!!!

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable)

[github-actions]

Unit Test Results (build & test)

  76 files  ±0    76 suites  ±0   25m 58s ⏱️ + 4m 17s
624 tests  - 6  564 ✔️  - 7  59 💤 ±0  1 ❌ +1 

For more details on these failures, see this check.

Results for commit 8872640. ± Comparison against base commit 787a7e6.

♻️ This comment has been updated with latest results.

[github-actions]

Unit Test Results (metadata ingestion)

       5 files         5 suites   44m 14s ⏱️
   347 tests    347 ✔️   0 💤 0 ❌
1 579 runs  1 548 ✔️ 31 💤 0 ❌

Results for commit 8872640.

♻️ This comment has been updated with latest results.