feat(search): Supporting Aggregations for hasX fields

[jjoyce0510]

Summary

In this PR, we introduce support for adding default aggregations returned in search queries for the Has X field extensions that we support in our @searchable annotations.

This will enable returning aggs for cases where it's important to understand a boolean rollup of a particular field. For example, to understand whether Assertions are failing for an asset, or whether an asset has owners, domains, glossary terms.

Also, added a new file for testing AggregationQueryBuilder. More tests will be necessary here.

Example

These changes add a few new fields to the Searchable annotation, which enable aggregation by default on the hasX existence extension fields:

@Searchable = {
  "fieldName": "owners",
  "fieldType": "URN",
  "addToFilters": true,
  "addHasValuesToFilters": true,
  "hasValuesFieldName": "hasOwners",
  "queryByDefault": false,
  "filterNameOverride": "Owned By",
  "hasValuesFilterNameOverride": "Has Owners"
}
owner: Urn

Status

Ready for review

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). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub

[david-leifker]

The changes themselves look good, I'd just want to see more complete testing. I know you've tested the added code path, but if possible exercising older path through the new logic would be good.