[core] Improve row id reassign retry reuse

[leaves12138]

Purpose

DataEvolutionRowIdReassigner can lose a commit race when a normal append commits a newer snapshot between planning and replaceManifestList. Previously the next reassignment invocation had to start the manifest read work from scratch.

Changes

• Retry replaceManifestList conflicts up to three times in the same reassignment call.
• Reuse already deserialized data manifest and index manifest entries across retry attempts.
• Recompute assignment from the latest snapshot and latest nextRowId on every retry to avoid row-id range overlap with concurrent appends.
• Add a deterministic conflict test that appends before the first reassign commit and verifies the retry uses the latest nextRowId.

Tests

• mvn -pl paimon-core spotless:apply
• mvn -pl paimon-core -am -Pfast-build -DfailIfNoTests=false -DwildcardSuites=none -Dtest=DataEvolutionRowIdReassignerTest#testReassignRetriesWithLatestNextRowIdAfterConcurrentAppend test
• mvn -pl paimon-core -am -DfailIfNoTests=false -DwildcardSuites=none -Dtest=DataEvolutionRowIdReassignerTest test
• git diff --check