Please do not put source control concerns in the .csproj (SccProjectName, etc)

If you create a new csproj, source control icons in Solution Explorer and change detection do not function properly, and when you open the project Visual Studio prompts you to select source control configuration. To make the problem go away, it inserts this in your csproj:

```xml

%24/TFS/Path
{SOME_GUID}
http://servername:8080/tfs/ProjectCollectionName
.

```

First, this is what the legacy csprojs had, and this also works:
```xml

SAK
SAK
SAK
SAK

```

But as should hopefully be clear from the second snippet, **this is not providing any information of value** which can't already be determined by looking at the workspace mapping. If this was a project under Git source control, that's exactly what Visual Studio would do. It should do the same for TFS and keep the csproj clean of such concerns.

Since you're improving the .csproj story with this project system, please be consistent and consistently separate concerns cleanly. A csproj should be able to go back and forth between Git and TFS source control without changing. The contents of the entire solution should be independent of its location.

No files, tests, or entry points are named. Trace where the project system generates or consumes SccProjectName, SccProvider, SccAuxPath, and SccLocalPath, then compare the legacy and Git behavior described here. Done means Visual Studio source-control behavior remains functional without adding source-control properties to the .csproj.

Written by the indexing model from the issue text.