[iceberg] Fix compaction commits emitting 'overwrite' instead of 'replace' in Iceberg snapshot operation

[0dunay0]

Summary

Fixes #7683.

When Paimon compacts an LSM table with the Iceberg metadata committer enabled, the resulting Iceberg snapshot has its operation field set to "overwrite". According to the Iceberg spec, compaction and file rewrite operations should use "replace" instead. Using "overwrite" makes downstream consumers like Polaris REST catalogs and query engines think the compaction was a data mutation, which is incorrect.

The problem was in IcebergCommitCallback.createWithDeleteManifestFileMetas(), which hardcoded IcebergSnapshotSummary.OVERWRITE whenever files were removed, without checking whether the commit was actually a compaction.

The fix:

• Add an IcebergSnapshotSummary.REPLACE constant for the "replace" operation
• Pass Snapshot.CommitKind into createWithDeleteManifestFileMetas() and use REPLACE when commitKind == COMPACT, OVERWRITE otherwise
• Add an assertion in IcebergCompatibilityTest.testDeleteImpl() to verify that compaction commits produce operation: "replace" in the Iceberg snapshot metadata

[0dunay0]

@JingsongLi @plusplusjiajia Please have a look at this PR

[JingsongLi]

+1