Get signed url with new storage account

List of changes done as part of this MR

1. Removed filePath from WorkflowTasksSharingDoc as it is no longer required.
2. Creation of new containers as part of generating signed urls for the given workflow run.
3. In case a container corresponding to the given workflowId already exists, the sas token will be generated for the same container.
4. Deletion of the container upon completion of a dag run (either success or failure)