Simplify capability matching

Remove type restrictions on capability matching to remove duplicate code.

Author: aristotelos

src/FlaUI.WebDriver/Controllers/SessionController.cs

@@ -142,24 +142,24 @@ private bool IsMatchingCapabilitySet(IDictionary<string, JsonElement> capabiliti
 
                 if (appPath != "Root")
                 {
-                    if(TryGetStringCapability(capabilities, "appium:appArguments", out _))
+                    if(capabilities.ContainsKey("appium:appArguments"))
                     {
                         matchedCapabilities.Add("appium:appArguments", capabilities["appium:appArguments"]);
                     }
                     if (!appPath.EndsWith("!App"))
                     {
-                        if (TryGetStringCapability(capabilities, "appium:appWorkingDir", out _))
+                        if (capabilities.ContainsKey("appium:appWorkingDir"))
                         {
                             matchedCapabilities.Add("appium:appWorkingDir", capabilities["appium:appWorkingDir"]);
                         }
                     }
                 }
             }
-            else if (TryGetStringCapability(capabilities, "appium:appTopLevelWindow", out _))
+            else if (capabilities.ContainsKey("appium:appTopLevelWindow"))
             {
                 matchedCapabilities.Add("appium:appTopLevelWindow", capabilities["appium:appTopLevelWindow"]);
             }
-            else if (TryGetStringCapability(capabilities, "appium:appTopLevelWindowTitleMatch", out _))
+            else if (capabilities.ContainsKey("appium:appTopLevelWindowTitleMatch"))
             {
                 matchedCapabilities.Add("appium:appTopLevelWindowTitleMatch", capabilities["appium:appTopLevelWindowTitleMatch"]);
             }