dotnet-svcutil --update should not reorder the class definitions

[EricStG]

Describe the bug
When updating a service reference based off the same exact WSDL, the order of the classes in the Reference.cs file changes, which makes it less version control friendly. It also makes it harder to determine what changed when the WSDL did change.

To Reproduce
Steps to reproduce the behavior:

1. Create a new service reference from a WSDL
2. Make a copy of the Reference.cs file
3. Run dotnet-svcutil --update with your service reference
4. Compare the Reference.cs files generated in step 2 and 3.

Expected behavior
When running dotnet-svcutil --update on a WSDL that has not change, the order of the classes in Reference.cs should stay the same.

Screenshots
N/A

Additional context
using dotnet-svcutil 2.0.1

[dasetser]

Thanks for the suggestion. This shouldn't impact functionality, but I can see why this would be nicer for version control and comparisons. We'll look into what we can do in a future version.