Support @projectedName for CADL+DPG

[lirenhe]

There is a feedback from archboard review meeting to rename a model in OpenAI.
We need to enable to support for @projectedName to handle this requirement.

Please check https://github.com/Azure/cadl-ranch/blob/main/packages/cadl-ranch-specs/http/projection/main.cadl for the test project.

CADL-dpg support is already done in https://github.com/Azure/cadl-azure/pull/2462.

[ArcturusZhang]

Some useful document: https://microsoft.github.io/typespec/standard-library/projected-names

By reading the document and some examples given, this looks like a pure emitter work.
The emitter needs to consume the decorator and put the "wire" values into the "serializedName" (for instance) and put the csharp or client names into its corresponding name of the property so that the generator could handle this automatically

[pshao25]

Please add tests by:

1. Add "projection" to $cadlRanchProjectPaths in eng\generated.ps1 and generate the SDK.
2. Add corresponding E2E tests under test\CadlRanchProjects.Tests.