Rename BearerTokenCredentialPolicy -> BearerTokenAuthorizationPolicy

[chlowell]

Two reasons "authorization" is better than "credential" here:

1. the policy authorizes requests with bearer tokens by setting the "Authorization" header
2. a TokenCredential could provide other types of token in addition to or instead of bearer tokens

[Copilot]

Pull Request Overview

This PR renames BearerTokenCredentialPolicy to BearerTokenAuthorizationPolicy to better reflect the policy's purpose of authorizing requests via the Authorization header, rather than focusing on the credential aspect. This clarifies that the policy handles authorization specifically for bearer tokens.

Key Changes

• Renamed the struct and all its references from BearerTokenCredentialPolicy to BearerTokenAuthorizationPolicy across the codebase
• Updated the CHANGELOG.md to document this breaking change

Reviewed Changes

Copilot reviewed 9 out of 20 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
sdk/core/azure_core/src/http/policies/bearer_token_policy.rs	Renamed struct and impl blocks from BearerTokenCredentialPolicy to BearerTokenAuthorizationPolicy
sdk/core/azure_core/src/http/policies/mod.rs	Updated public export to use new policy name
sdk/storage/azure_storage_blob/src/clients/page_blob_client.rs	Updated import to use renamed policy
sdk/storage/azure_storage_blob/src/clients/block_blob_client.rs	Updated import to use renamed policy
sdk/storage/azure_storage_blob/src/clients/blob_service_client.rs	Updated import to use renamed policy
sdk/storage/azure_storage_blob/src/clients/blob_container_client.rs	Updated import to use renamed policy
sdk/storage/azure_storage_blob/src/clients/blob_client.rs	Updated import to use renamed policy
sdk/storage/azure_storage_blob/src/clients/append_blob_client.rs	Updated import to use renamed policy
sdk/core/azure_core/CHANGELOG.md	Added breaking change entry for the rename