Implemented vstest verb which will run the test from given container. (#4115)

* Implemented vstest verb which will run the test from given container.

* Fixed Nitpick.

* 1) Addressed PR comment
2) Added tests for vstest verb

* Using specific version of Microsoft.TestPlatform.

* Address PR comments.

Modified help text for the vstest command.
Removed unused function.

* Fixed package related issue.
--Taking reference of microsoft.testplatform.cli nuget package which has contentFolder in it so that sub folder of this nuget can also be added in cli package.
-- Removing vstest.console, vshost and datacollector from Bundletools as we dont want *.deps.json to be override

* Nitpick

* Making vstest.console arguments compatible for non windows platform

* Fix tests to run on linux machine

* Updated the microsoft.testplatform.cli nuget package version. This version has fix related to non windows machine.

* changed dapter path from bin/debug to bin/Debug

* updated nuget version of package Microsoft.TestPlatform.CLI.

* Revert "updated nuget version of package Microsoft.TestPlatform.CLI."

This reverts commit bcc26c21d11c2bd2e5259a74f9890b0fd75962c7.

* Updated version of nuget package Microsoft.TestPlatform.CLI
Added Test project in solution file

* Addressed PR comment.

* Removed unnecessary --platform argument from test

TestAssets/TestProjects/VSTestDotNetCoreProject/Tests.cs

@@ -0,0 +1,19 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace TestNamespace
+{
+    [TestClass]
+    public class VSTestTests
+    {
+        [TestMethod]
+        public void VSTestPassTest()
+        {
+        }
+		
+		[TestMethod]
+        public void VSTestFailTest()
+        {
+			Assert.Fail();
+        }
+    }
+}