Low hanging fruit performance improvements from profiling session

[davidfowl]

• Don't use Tracing system for logging, use Console.WriteLine for now. Trace loads the entire configuration stack.
• Don't use ToObject when parsing global/project.json, that causes the data contract serialization stack to load in JSON.NET which isn't required at all.
• Don't use JsonSerializer.SerializeObject<T> when a simple JObject/JToken can be used. The DesignTime host runtime component should send JObject.
• Don't use JToken.FromObject when you know the shape of the object.
• LockFilePackage should not return PhysicalPackageFiles since it parses target framework names (TODO: double check this).
• Use Count > 0 in the graph walking ForEach extension method.
• ResolvePackagePath reads sha512 files from the disk when it doesn't need to.
• TryGetCompatibleItems reads all of the potable profiles at once.
• FrameworkNameUtility.ParseFrameworkName doesn't have to understand all runtimes and should not use regular expressions. It can just hard code to 2 of them that it knows about.
• Regex use in SemanticVersion and VersionUtility.ParseFrameworkName should be removed.
• Remove logging from WalkContext that prints the graph.
• Cache project.json parsing for resolved projects.
• Remove reflection from LibraryDependencyType and LibraryDependencyTypeKeyword
• New up socket on another thread.