[fix][io] Fix builtin sink transformation on k8s

[cbornet]

Motivation

Fixes a NPE with transform-function+Sink on k8s because builtin is null in getFunctionPackageLocation.
There is no issue when not in k8s because then the packageUrl is used for the packagePath and its value is builtin://xxx

Modifications

Use the builtin from the functionDetails that was previously set in SinkConfigUtils::convert

Verifying this change

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This change is a trivial rework / code cleanup without any test coverage.

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• Added integration tests for end-to-end deployment with large payloads (10MB)
• Extended integration test for recovery after broker failure

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

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• Dependencies (add or upgrade a dependency)
• The public API
• The schema
• The default values of configurations
• The binary protocol
• The REST endpoints
• The admin CLI options
• Anything that affects deployment

Documentation

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Matching PR in forked repository

PR in forked repository: cbornet#3

[eolivelli]

LGTM

[codecov-commenter]

Codecov Report

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