Microsoft.DiaSymReader.Pdb2Pdb package as dotnet tool

[dominoFire]

Consider packing Microsoft.DiaSymReader.Pdb2Pdb package as dotnet tool. That way, we can use dotnet tool commands to manage the package, instead of installing it in a fixed location and creating custom scripts to invoke pdb2pdb.exe.

This would require adding the following properties to the project file:

<PackAsTool>true</PackAsTool>
<ToolCommandName>pdb2pdb</ToolCommandName>