Split browser and browser context (#2572)

* Split browser and browser context

* Docs changes

* Move connection

* Fix CDPSession

* more fixes

* some fixes

---------

Co-authored-by: GitHub Action <[email protected]>

Author: kblok

lib/PuppeteerSharp.Tests/TargetManagerTests/TargetManagerTests.cs

@@ -4,6 +4,7 @@
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
 using NUnit.Framework;
+using PuppeteerSharp.Cdp;
 using PuppeteerSharp.Helpers;
 using PuppeteerSharp.Nunit;
 
@@ -25,7 +26,7 @@ public TargetManagerTests() : base()
         [Test, Retry(2), PuppeteerTest("TargetManager.spec", "TargetManager", "should handle targets")]
         public async Task ShouldHandleTargets()
         {
-            var targetManager = (Browser as Browser).TargetManager;
+            var targetManager = (Browser as CdpBrowser)!.TargetManager;
             Assert.AreEqual(2, targetManager.GetAvailableTargets().Values.Count);
 
             Assert.IsEmpty(await Context.PagesAsync());