Provide ability to direct restore a URL (with a CREDENTIAL) instead of copying to container first

[stuartpa]

Right now the sqlcmd use functionality copies the file to the container, and then before the action to restore/attach etc.

This comment in a code review suggests we enable the ability to restore the URL directly from the sqlservr process in the container (avoiding the need for the copy to container)

"for .bak files using a URL we should provide a way to create a CREDENTIAL to store on the server so it can restore directly from the URL.
SQL 2022 supports both https and s3 URLs"