[AzCopy] [Storage] PageBlobClient NewGetPageRangesPager panics if nil options bag is passed

[gapra-msft]

Bug Report

• import path of package in question .../storage/azblob
• SDK version latest,

• What happened?
  When pageblob.Client.NewGetPageRangesPager(nil) is called and there is a second page expected, the Go SDK panics since it tries to set the NextMarker parameter on a nil options bag. L234 in pageblob/client.go

Mitigation is to pass an empty options bag and instead call it this way pageblob.Client.NewGetPageRangesPager(&pageblob.GetPageRangesOptions{})

• What did you expect or want to happen?
  Go SDK should check if PageRangeOptions is nil and set it to the empty options bag.

• How can we reproduce it?
  Instructions given above

• Anything we should know about your environment.
  N/A