When BlobEndpoint is not configured use AccountName in connection string for Azure blob store connector

Currently, when using shared access signature, connection string is only possible to configure with

BlobEndpoint.

If blob endpoint is missing in the configuration, it should be possible to configure connection string also with AccountName.

https://github.com/apache/jackrabbit-oak/blob/jackrabbit-oak-1.42.0/oak-blob-cloud-azure/src/main/java/org/apache/jackrabbit/oak/blob/cloud/azure/blobstorage/Utils.java#L145