Dotnet should "@" names conflicting keywords in template

[livarcocc]

From @hsorbo on December 6, 2017 20:33

dotnet new may end up creating invalid-code if its folder conflicts with a keyword
Example:

using System;

namespace class
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");
        }
    }
}

Steps to reproduce

mkdir class
cd class
dotnet new console
dotnet build

Expected behavior

compiles

Actual behavior

Program.cs(3,11): error CS1001: Identifier expected [***/class/class.csproj]
Program.cs(3,11): error CS1514: { expected [***/class/class.csproj]
Program.cs(3,16): error CS1001: Identifier expected [***/class/class.csproj]
Program.cs(4,2): error CS1513: } expected [***/class/class.csproj]

Environment data

.NET Command Line Tools (2.0.3)

Product Information:
 Version:            2.0.3
 Commit SHA-1 hash:  eb1d5ee318

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  10.13
 OS Platform: Darwin
 RID:         osx.10.12-x64
 Base Path:   /usr/local/share/dotnet/sdk/2.0.3/

Microsoft .NET Core Shared Framework Host

  Version  : 2.0.3
  Build    : a9190d4a75f4a982ae4b4fa8d1a24526566c69df```







_Copied from original issue: dotnet/cli#8175_

[mlorbetske]

This is being tracked as #381