feat: add additive blob bucket support [6/n]

[sadhansood]

Description

This adds additive blob bucket support to walrus-sui without widening the existing owned blob APIs.

It introduces bucket-specific Move bindings and Rust types for BlobBucket, BlobBucketCap, and PooledBlob, plus new PTB and client methods for:

• creating a blob bucket
• registering pooled blobs
• certifying pooled blobs
• deleting pooled blobs
• extending the backing storage pool
• increasing backing storage pool capacity

The client resolves the blob bucket package from the bucket object itself, so bucket package/version handling stays local to the new bucket APIs instead of being pushed into the global contract config.

This PR also updates the local test publishing path to publish the blob_bucket package, threads that package ID through SystemContext, and adds an end-to-end bucket lifecycle test covering create, register, certify, extend, increase-capacity, and delete.

Test plan

• rustup run 1.86 cargo fmt -- --config group_imports=StdExternalCrate,imports_granularity=Crate,imports_layout=HorizontalVertical
• cargo clippy --workspace --all-features --tests --no-deps -- -D warnings
• cargo check -p walrus-sui --tests --all-features
• cargo test -p walrus-sui --all-features test_blob_bucket_lifecycle -- --ignored

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