Use sas token for attachment downloads (#1153)

* Get limited life attachment download URL

This change limits url download to a 1min lifetime.
This requires moving to a new container to allow for non-public blob
access.

Clients will have to call GetAttachmentData api function to receive the download
URL. For backwards compatibility, attachment URLs are still present, but will not
work for attachments stored in non-public access blobs.

* Make GlobalSettings interface for testing

* Test LocalAttachmentStorageService equivalence

* Remove comment

* Add missing globalSettings using

* Simplify default attachment container

* Default to attachments containe for existing methods

A new upload method will be made for uploading to attachments-v2.
For compatibility for clients which don't use these new methods, we need
to still use the old container. The new container will be used only for
new uploads

* Remove Default MetaData fixture.

* Keep attachments container blob-level security for all instances

* Close unclosed FileStream

* Favor default value for noop services

test/Core.Test/TempDirectory.cs

@@ -0,0 +1,42 @@
+using System;
+using System.IO;
+
+namespace Bit.Core.Test
+{
+    public class TempDirectory : IDisposable
+    {
+        public string Directory { get; private set; }
+
+        public TempDirectory()
+        {
+            Directory = Path.Combine(Path.GetTempPath(), $"bitwarden_{Guid.NewGuid().ToString().Replace("-", "")}");
+        }
+
+        public override string ToString() => Directory;
+
+        #region IDisposable implementation
+        ~TempDirectory()
+        {
+            Dispose(false);
+        }
+
+        public void Dispose()
+        {
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        public void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                try
+                {
+                    System.IO.Directory.Delete(Directory, true);
+                }
+                catch { }
+            }
+        }
+        # endregion
+    }
+}