refactor(search): share SortedUnionKeys + Classification.AddBreaking

Browse Source

- export mapping.SortedUnionKeys and reuse it in bleve.compareKeysExcept
  instead of a copied union-of-keys block
- add Classification.AddBreaking to fold engine-specific breaking reasons and
  force the verdict, replacing the identical block in the bleve and opensearch
  Classify paths

...

This commit is contained in:

500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f