feat: Added ODPEventManager implementation (#320)

* WIP initial ODP event manager

* Finish implementing ODP Event Manager; scaffolding tests

* WIP ODP Event Manager unit tests

* WIP unit tests & fixes

* Post merge fixes

* WIP Fixing code & tests

* Additional unit tests added

* Upgraded NUnit+fixed upgrade errors; finished tests

Needed control over threading/non-parallel test execution

* Internal doc + fix NuGet ref

* Doc & fix

* Use CountdownEvent

Thanks to finding Java's CountDownLatch :-)

* Pull request code review changes

* Fix batch detection

* Legacy changes rollback; Adjust Event Manager test

* Fix lint whitespace

* PR code revisions

* Pull request code review changes

* Better handling of Cancel to _flushIntervalCancellation token

* Lint fixes

* PR review changes

* Pull request changes

* Fix lint

* Test and lint fixes

* Update OptimizelySDK/Odp/OdpEventManager.cs

Co-authored-by: Jae Kim <45045038+jaeopt@users.noreply.github.com>

* Additional lock when emptying queue

* Rollback select files

* Requested code changes to model BatchEventProcessor

* Remove unneeded test

* Pull Request changes

* Linter corrections

* Bug fix

* Pull request code review changes

* Revert accidental file inclusion

Co-authored-by: Sohail Hussain <mirza.sohailhussain@gmail.com>
Co-authored-by: Jae Kim <45045038+jaeopt@users.noreply.github.com>

Author: 3 people

OptimizelySDK.Tests/OdpTests/HttpClientTestUtil.cs

@@ -40,33 +40,35 @@ public static HttpClient MakeHttpClient(HttpStatusCode statusCode,
         )
         {
             var response = new HttpResponseMessage(statusCode);
-            
+
             if (!string.IsNullOrWhiteSpace(content))
             {
                 response.Content = new StringContent(content);
             }
 
             var mockedHandler = new Mock<HttpMessageHandler>();
-            mockedHandler.Protected().Setup<Task<HttpResponseMessage>>(
+            mockedHandler.Protected()
+                .Setup<Task<HttpResponseMessage>>(
                     "SendAsync",
                     ItExpr.IsAny<HttpRequestMessage>(),
-                    ItExpr.IsAny<CancellationToken>()).
-                ReturnsAsync(response);
+                    ItExpr.IsAny<CancellationToken>())
+                .ReturnsAsync(response);
             return new HttpClient(mockedHandler.Object);
         }
-        
+
         /// <summary>
         /// Create an HttpClient instance that will timeout for SendAsync calls
         /// </summary>
         /// <returns>HttpClient instance that throw TimeoutException</returns>
         public static HttpClient MakeHttpClientWithTimeout()
         {
             var mockedHandler = new Mock<HttpMessageHandler>();
-            mockedHandler.Protected().Setup<Task<HttpResponseMessage>>(
+            mockedHandler.Protected()
+                .Setup<Task<HttpResponseMessage>>(
                     "SendAsync",
                     ItExpr.IsAny<HttpRequestMessage>(),
-                    ItExpr.IsAny<CancellationToken>()).
-                Throws<TimeoutException>();
+                    ItExpr.IsAny<CancellationToken>())
+                .Throws<TimeoutException>();
             return new HttpClient(mockedHandler.Object);
         }
     }