api-doc-tools #945509 Support ref readonly parameters

Work item: https://ceapex.visualstudio.com/Engineering/_workitems/edit/945509

Add support for correct rendering of "ref readonly" parameter in C# method signature documentation.

Added one unit test and also verified output against the case mentioned in the work item (https://learn.microsoft.com/en-us/dotnet/api/system.runtime.compilerservices.unsafe.asref?view=net-8.0#system-runtime-compilerservices-unsafe-asref-1%28-0@%29 should render with scoped ref readonly T source instead of scoped ref T source.

I couldn't get the C++ tests running but they appear to be out of scope here.

Sep 25 '24 16:09 nickwalkmsft

https://ceapex.visualstudio.com/Engineering/_build/results?buildId=1868433

Sep 26 '24 09:09 v-fuquanli

/azp run

Nov 15 '24 10:11 xmdanni

Azure Pipelines successfully started running 1 pipeline(s).

Nov 15 '24 10:11 azure-pipelines[bot]

https://dev.azure.com/ceapex/Engineering/_build/results?buildId=1919824

Nov 15 '24 10:11 xmdanni

/azp run

Oct 29 '25 06:10 bianyifan

Azure Pipelines successfully started running 1 pipeline(s).

Oct 29 '25 06:10 azure-pipelines[bot]

https://dev.azure.com/ceapex/Engineering/_build/results?buildId=2294644

Oct 29 '25 06:10 xmdanni

/azp run

Oct 29 '25 08:10 bianyifan

Azure Pipelines successfully started running 1 pipeline(s).

Oct 29 '25 08:10 azure-pipelines[bot]

https://dev.azure.com/ceapex/Engineering/_build/results?buildId=2294747

Oct 29 '25 08:10 xmdanni

/azp run

Oct 29 '25 08:10 bianyifan

Azure Pipelines successfully started running 1 pipeline(s).

Oct 29 '25 08:10 azure-pipelines[bot]

https://dev.azure.com/ceapex/Engineering/_build/results?buildId=2294773

Oct 29 '25 08:10 xmdanni