feat(cinder): Add get attachments tool(#70)

- Add get attachments tool
- Tests are updated and passing

Author: S0okJu

src/openstack_mcp_server/tools/response/block_storage.py

@@ -43,10 +43,9 @@ class Attachment(BaseModel):
     connection_info: ConnectionInfo | None = None
     connector: str | None = None
 
-      
+
 class AttachmentSummary(BaseModel):
     id: str
     instance: str
     volume_id: str
     status: str
-