Applying code style rules

[shawncal]

Updating to latest style guidelines

• Newline between methods, properties, and after each closing brace }
• Adding visibility modifiers to all members
• Eliminating private member vars when a public auto-prop is available
• Using pattern matching for is null and is not null (instead of == null and != null)
• Using expression syntax for single-line methods
• CancellationTokens parameters all called cancellationToken (common across dotnet) and public async methods have a default value, making the cancellation token optional
• Adding missing ConfigureAwait(false) on some async calls
• Other misc minor fixes and optimizations