Changing --version in the CLI

`dotnet --version` returns just the version number. This helps tools get this information without having to parse the full info.
Introduce a new argument `--info` that returns the current "long form". With this, we also change the long form to say "RID" instead of "Runtime ID" simply because that would avoid any future localization issues and thus make the parsing easier.

Fix #1607 #1882

src/dotnet/commands/dotnet-help/HelpCommand.cs

@@ -17,7 +17,8 @@ Arguments:
 
 Common Options (passed before the command):
   -v|--verbose  Enable verbose output
-  --version     Display .NET CLI Version Info
+  --version     Display .NET CLI Version Number
+  --info        Display .NET CLI Info
 
 Common Commands:
   new           Initialize a basic .NET project