[FLINK-38765] Fix persisted metadata handling in sink

[dawidwys]

What is the purpose of the change

Fixes a bug where an incorrect type is used in sink for

• shuffling
• sink upsert materializer
• constraint validation

Verifying this change

Added a test in SinkTestPrograms

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:

• 1bbc56907549560844f19de262c9e1f80dc272ac UNKNOWN
• 7d514b9aeb2376bce91a706fa23981eceaf0122d UNKNOWN
• 07fa646a9b301dcd979f3a1fd7346ab92221ff2c Azure: SUCCESS
• 75e2ffb44b788b179ad26b0bfdea4c8a6a8ec0a0 Azure: PENDING

Bot commands

The @flinkbot bot supports the following commands:

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

[dawidwys]

Thank you. I'll just squash the commits to run the CI on a final version that I can merge 👍