feat: implement blob versioning support

[Copilot]

Azurite had no support for Azure Blob Storage versioning — overwriting a blob should preserve the previous content as a named version accessible by versionId. This adds versioning lifecycle support to the Loki-backed blob metadata store.

Model & XML Serialization

• Added BlobVersioning interface ({ enabled?: boolean }) and replaced the flat isVersioningEnabled field on StorageServiceProperties with a proper versioning?: BlobVersioning composite field
• Added BlobVersioning composite mapper so <Versioning><Enabled>true</Enabled></Versioning> round-trips correctly via msrest XML serialization

Metadata Store (LokiBlobMetadataStore)

• createBlob / commitBlockList: when versioning is enabled, marks the existing blob as isCurrentVersion: false (instead of deleting) and inserts the new blob with a fresh versionId and isCurrentVersion: true
• getBlobWithLeaseUpdated: accepts optional versionId for direct version lookup; without it, filters out isCurrentVersion === false blobs so non-versioned callers are unaffected
• listBlobs: added includeVersions flag; when false (default), previous versions are hidden
• deleteBlob: when versionId is specified, removes only that version

HTTP Handlers

• BlobHandler / BlockBlobHandler: propagate versionId option into store calls and surface versionId / isCurrentVersion in responses
• ContainerHandler: parses include=versions from list requests and passes includeVersions to listBlobs; emits versionId / isCurrentVersion per blob item

Usage example

// Enable versioning (requires raw HTTP — SDK does not expose this yet)
await setServiceProperties(`<Versioning><Enabled>true</Enabled></Versioning>`);

const blobClient = containerClient.getBlockBlobClient("myblob");
const v1 = await blobClient.upload("version1", 8);  // v1.versionId set
const v2 = await blobClient.upload("version2", 8);  // v2.versionId set, v1 preserved

// Download a previous version
const old = await blobClient.withVersion(v1.versionId!).download();

// List all versions
for await (const blob of containerClient.listBlobsFlat({ includeVersions: true })) {
  console.log(blob.versionId, blob.isCurrentVersion);
}

// Delete a specific version
await blobClient.withVersion(v1.versionId!).delete();

• Fixes Enable Blob versioning #665