[FLINK-36455] Sinks retry synchronously

[AHeise]

What is the purpose of the change

Sinks so far retried asynchronously to increase commit throughput in case of temporary issues. However, the contract of notifyCheckpointCompleted states that checkpoints must be side-effect free meaning all transactions have to be committed on return of the PRC call.

Brief change log

• This commit retries a fixed number of times and then fails in notifyCheckpointCompleted.
• Simplifies parts of committable handling now that all committables of a subtask either succeed or fail

Verifying this change

• Already covered by many tests
• Adjusted and changed tests in api/connector/sink2 runtime/operators/sink/committables

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (yes / no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (yes / no)
• The serializers: (yes / no / don't know)
• The runtime per-record code paths (performance sensitive): (yes / no / don't know)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (yes / no / don't know)
• The S3 file system connector: (yes / no / don't know)

Documentation

• Does this pull request introduce a new feature? (yes / no)
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)

[flinkbot]

CI report:

• 64a5257ac25ccffbaa643b71e533f01578755d3b Azure: SUCCESS

Bot commands

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• @flinkbot run azure re-run the last Azure build

[AHeise]

Reverted the deprecation of numFailed and added a config option for the retries. PTAL @fapaul