Adding pausing functionality for the profiler (#634)

* Dropping profiler session on stop request

* Changes to IXEventSession to simplify dropping sessions

* Stop sessions instead of dropping, disable flaky tests

* Initial framework for profiler pause requests

* Restructuring profiler session monitoring

* Fixes to session monitor

* Testing for pause functionality

* Fixing comments from PR

* Changes to testing

* Commenting out flaky test

* Deleting leftover testing code

src/Microsoft.SqlTools.ServiceLayer/Profiler/IXEventSession.cs

@@ -11,13 +11,23 @@ namespace Microsoft.SqlTools.ServiceLayer.Profiler
     public interface IXEventSession
     {
         /// <summary>
-        /// Reads XEvent XML from the default session target
+        /// Gets unique XEvent session Id
         /// </summary>
-        string GetTargetXml();
+        int Id { get; }
+
+        /// <summary>
+        /// Starts XEvent session
+        /// </summary>
+        void Start();
 
         /// <summary>
         /// Stops XEvent session
         /// </summary>
         void Stop();
+
+        /// <summary>
+        /// Reads XEvent XML from the default session target
+        /// </summary>
+        string GetTargetXml();
     }
 }