Add support for new keyword in apiview for dotnet

Right now the `new` keyword is not added to the apiview which means we cannot see changes to this portion of the api.

As an example [this PR](https://github.com/Azure/azure-sdk-for-net/pull/31311/files#diff-27189525a4463302c33017ff79839674b0eb26cd496832619e83830918288ad0R109) is adding the `new` keyword to the `Get` method but the diff in [apiview ](https://apiview.dev/Assemblies/Review/1b6fb5729cec41afb1e48f131554e7b3/a250c224d8ef4fbd829be8b1df2e5ce7?diffRevisionId=8bd38f4a19c44545ba548c1367e56bf7&doc=False&diffOnly=True) does not show this.

Can we add support to both show this keyword in apiview if it exists and show it as a diff when the keyword is added or removed?

Start by reproducing the linked APIView diff for the .NET `Get` method and trace the APIView entry point that renders API members. The work is done when existing and newly added or removed `new` keywords appear in APIView and are shown in diffs.

Written by the indexing model from the issue text.