Resource monitor (Azure#48501)

* create cpu monitor

- create method for monitoring CPU usage that works for all frameworks using System.Diagnostics.Process
- create one test for ensuring that the monitor works

* update cpu monitor logic

- add CpuMonitor interface
- add CpuMonitor tests
- change CurrentProcessorTime to be the current time on the processor minute the previous

* finished baseline cpu tuner

- removed unnecessary refactor
- add SimulateCpuLoad to test suite to simulate loading the CPU
- add CoreCount Property to replace function calls to Environment.ProcessorCount

* add testing

- readd default constructor
- add tests for monitoring interval that is below 100 milliseconds

* create memory monitor

- create processor directive to create memory monitor for netstandard2.0 or greater, but this is not a great implementation
- create method for MonitorMemoryUsage is otherwise good
- create tests to check whether it is below 1, above 0, and not null

* add memory check for netstandard20

* rename CpuMonitor to ResourceMonitor

* fix merge issue and add changes

- remove interface
- change private properties to fields
- group private fields and properties
- remove public default constrcutor
- combine CPU and memory into one task and run on single thread
- switch order in resource monitor: take reading first, then sleep
- memory monitor returns Bytes instead of percentage
- remove all functionality for getting total memory

* change interface to concrete class

* update tests

* removed tests and updated resource monitor

* increase simulate load time for mac

* add functionality for mac os

Author: t-davidbrown-msft

sdk/storage/Azure.Storage.DataMovement/src/ConcurrencyTuner/ConcurrencyTuner.cs

@@ -18,7 +18,7 @@ internal class ConcurrencyTuner
     {
         internal int _initialConcurrency;
         internal int _maxConcurrency;
-        public static CpuMonitor _cpuPerformance;
+        public static ResourceMonitor _resourceMonitor;
         internal int _finalReason; // ConcurrencyTunerState
         internal int _finalConcurrency;
         internal SemaphoreSlim _lockFinal;
@@ -31,7 +31,7 @@ public ConcurrencyTuner(
         {
             _initialConcurrency = initialConcurrency;
             _maxConcurrency = maxConcurrency;
-            _cpuPerformance = new CpuMonitor();
+            _resourceMonitor = new ResourceMonitor();
             _finalReason = (int) ConcurrencyTunerState.ConcurrencyReasonNone;
             _finalConcurrency = _initialConcurrency;
             _observations = Channel.CreateUnbounded<ConcurrencyObservation>();