HDDS-13919. S3 Conditional Writes (PutObject) [2/2] - Reuse Atomic Rewrite at Commit Path

[peterxcli]

What changes were proposed in this pull request?

OM Create Phase
Validation is performed within the validateAndUpdateCache method to ensure atomicity within the Ratis state machine application.

1. Locking: The OM acquires the write lock for the bucket/key.
2. Key Lookup: Retrieve the existing key from KeyTable.
3. Validation:
   • Key Not Found: If the key does not exist, throw KEY_NOT_FOUND (maps to S3 412).
   • No ETag Metadata: If the existing key (e.g., uploaded via OFS) does not have an ETag property, throw ETAG_NOT_AVAILABLE (maps to S3 412). The precondition cannot be evaluated, so we must fail rather than silently proceed.
   • ETag Mismatch: Compare existingKey.ETag with expectedETag. If they do not match, throw ETAG_MISMATCH (maps to S3 412).
4. Extract Generation: If ETag matches, extract existingKey.updateID.
5. Create Open Key: Create open key entry with expectedDataGeneration = existingKey.updateID.

Sorry I forgot to follow the step 4 and 5 in my previous PR #9815 ...

What is the link to the Apache JIRA

issues.apache.org/jira/browse/HDDS-13919

How was this patch tested?

existing tests

[yandrey321]

it seems like the same logic ad in CommitRequest