PerfCounterSample's instance field is truncated if contains '#' symbol #6

PerfCounterSample's instance field is truncated if contains '#' symbol.

Repro steps:

• Start multiple instances of LINQpad for example
• Collect any process counters for process with LINQpad.UserQuery#1 instance name. Use the following code snippet: PerfCounterObservable.FromRealTime(TimeSpan.FromSeconds(1), @"\Process(LINQPad.UserQuery#1)\Private Bytes").Dump()
• See that instances in the result set will be truncated to LI