[Storage] content_length -> size for PageBlobClient create API

[vincenttran-msft]

As title states.
.tsp: Azure/azure-rest-api-specs#39097

[github-actions]

API Change Check

APIView identified API level changes in this PR and created the following API reviews

azure_storage_blob

[Copilot]

Pull request overview

This PR updates the Azure Storage Blob SDK to align with the latest TypeSpec definitions from azure-rest-api-specs. The primary changes involve renaming parameters for clarity and updating immutability policy-related APIs.

Key changes:

• Renamed content_length/blob_content_length parameters to size in PageBlobClient's create() and resize() methods for better clarity
• Consolidated BlobImmutabilityPolicyMode into ImmutabilityPolicyMode with updated serialization format (lowercase) and added Mutable variant
• Updated immutability policy APIs: made expiry a required parameter in set_immutability_policy() and simplified return types to Response<(), NoFormat> for several blob operations

Reviewed changes

Copilot reviewed 4 out of 12 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
sdk/storage/azure_storage_blob/tsp-location.yaml	Updated commit hash reference to latest TypeSpec definitions
sdk/storage/azure_storage_blob/src/models/mod.rs	Removed exports for deleted immutability policy result types and headers
sdk/storage/azure_storage_blob/src/generated/models/pub_models.rs	Changed BlobImmutabilityPolicyMode to ImmutabilityPolicyMode and removed obsolete result structs
sdk/storage/azure_storage_blob/src/generated/models/method_options.rs	Removed immutability_policy_expiry from options (now a required parameter)
sdk/storage/azure_storage_blob/src/generated/models/header_traits.rs	Removed header traits for deleted result types and updated references to ImmutabilityPolicyMode
sdk/storage/azure_storage_blob/src/generated/models/enums_serde.rs	Removed serialization code for BlobImmutabilityPolicyMode
sdk/storage/azure_storage_blob/src/generated/models/enums_impl.rs	Removed implementation for BlobImmutabilityPolicyMode and updated ImmutabilityPolicyMode with lowercase serialization and Mutable variant
sdk/storage/azure_storage_blob/src/generated/models/enums.rs	Removed BlobImmutabilityPolicyMode enum and updated ImmutabilityPolicyMode with Mutable variant
sdk/storage/azure_storage_blob/src/generated/clients/page_blob_client.rs	Renamed blob_content_length parameter to size in create() and resize() methods
sdk/storage/azure_storage_blob/src/generated/clients/blob_client.rs	Updated immutability policy methods: made expiry required, changed return types to Response<(), NoFormat>, removed documentation for deleted header traits
sdk/storage/azure_storage_blob/src/clients/page_blob_client.rs	Updated public wrapper to use size parameter name in create() method
sdk/storage/azure_storage_blob/CHANGELOG.md	Added entry for create() parameter rename (incomplete - missing several breaking changes)