feat(changeProcessing): Change Processing Proposal

[matthewc-gr]

Proposal for processing changes before and after they are applied to the underlying datastore.

Summary: Allows users to create a jar that contains custom processing code that adheres to an interface that DataHub declares. Processor logic is then run before and after the change is applied to the data store.

More information can be found at: https://github.com/matthewc-gr/datahub/blob/custom-update-lambdas/docs/rfc/active/000-change-processor/README.md

[github-actions[bot]]

Unit Test Results

  10 files   -   26    10 suites   - 26   22m 21s :stopwatch: - 4m 6s 239 tests  - 249  236 :heavy_check_mark:  - 200    0 :zzz:  - 52  3 :x: +3  913 runs   - 249  886 :heavy_check_mark:  - 208  22 :zzz:  - 46  5 :x: +5 

For more details on these failures, see this check.

Results for commit 81449a32. ± Comparison against base commit ec406c79.

[jjoyce0510]

Closing, being replaced by Atomic Updates.