Analyzer node files paths are invalid

Each tree node representing a analyzer in the dependency tree is returning the following as its moniker/canonical name/FilePath:

```
[project-directory]\[target-framework]\AnalyzerDependency\[full-path-of-analyzer]
```

For example:
```
c:\users\davkean\Source\Repos\ConsoleApp61\ConsoleApp61\netcoreapp1.1\AnalyzerDependency\C:\Users\davkean\.nuget\packages\microsoft.codeanalysis.analyzers\1.1.0\analyzers\dotnet\cs\Microsoft.CodeAnalysis.Analyzers.dll
```

I believe we expect the moniker to be the analyzer file path, so this is likely breaking something @tmeschter what would be broken by this?