[Storage] undelete for BlobClient

[vincenttran-msft]

.tsp: Azure/azure-rest-api-specs#39068

This PR adds the following:

• undelete API for BlobClient
• Enables soft delete on the "Standard" account defined in the test-resources.bicep

Sanity run of the live tests to ensure that enabling soft-delete didn't cause any weird failures: https://dev.azure.com/azure-sdk/internal/_build/results?buildId=5634022&view=results

• Added missing changelog entries for previously merged PRs and this current PR

[Copilot]

Pull request overview

This PR adds blob undelete functionality to the Azure Storage Blob SDK for Rust, enabling recovery of soft-deleted blobs. The changes include both the API implementation and test infrastructure updates to support soft delete testing.

• Implements undelete method on BlobClient to restore soft-deleted blobs
• Enables soft delete with 1-day retention on the test storage account
• Updates generated code from upstream Azure REST API specifications (commit e7ed1502)

Reviewed changes

Copilot reviewed 7 out of 14 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
sdk/storage/test-resources.bicep	Adds blob services configuration with soft delete and container delete retention policies (1-day retention for testing)
sdk/storage/azure_storage_blob/tsp-location.yaml	Updates commit reference for TypeSpec code generation
sdk/storage/azure_storage_blob/tests/blob_client.rs	Adds comprehensive test for undelete functionality, verifying blob can be restored after soft delete
sdk/storage/azure_storage_blob/src/clients/blob_client.rs	Adds public undelete method with proper documentation
sdk/storage/azure_storage_blob/src/models/mod.rs	Updates exports to include BlobClientUndeleteOptions and removes obsolete types
sdk/storage/azure_storage_blob/src/generated/models/pub_models.rs	Consolidates immutability policy types, removing duplicate BlobImmutabilityPolicyMode
sdk/storage/azure_storage_blob/src/generated/models/method_options.rs	Refactors immutability policy options structure
sdk/storage/azure_storage_blob/src/generated/models/header_traits.rs	Updates header traits to use consolidated ImmutabilityPolicyMode
sdk/storage/azure_storage_blob/src/generated/models/enums_serde.rs	Removes duplicate enum serialization code
sdk/storage/azure_storage_blob/src/generated/models/enums_impl.rs	Updates ImmutabilityPolicyMode enum to use lowercase variants and adds "mutable" variant
sdk/storage/azure_storage_blob/src/generated/models/enums.rs	Removes duplicate BlobImmutabilityPolicyMode, updates ImmutabilityPolicyMode documentation
sdk/storage/azure_storage_blob/src/generated/clients/blob_client.rs	Implements generated undelete method and refactors immutability policy methods
sdk/storage/azure_storage_blob/assets.json	Updates test assets tag reference
sdk/storage/.dict.txt	Adds "Undeletes" to dictionary for spell checking