Modernization + AZStd::function compare fix. (#3680)

* Modernization + small fix.

Modernize ( `bool`/`override`/other) code in AzCore, AzFramework, AzQtComponents, AzToolsFramework, etc.
Replaced a `bind` or two, use `using` in a few places as well.

Fix nullptr comparison of AZStd::function.

Signed-off-by: nemerle <96597+nemerle@users.noreply.github.com>

* Apply review-based changes

Signed-off-by: nemerle <96597+nemerle@users.noreply.github.com>

Code/Framework/AzToolsFramework/Tests/EntityInspectorTests.cpp

@@ -67,7 +67,7 @@ namespace UnitTest
             services.push_back(AZ_CRC("InspectorTestService1"));
         }
 
-        virtual ~Inspector_TestComponent1() override
+        ~Inspector_TestComponent1() override
         {
         }
 
@@ -136,7 +136,7 @@ namespace UnitTest
             services.push_back(AZ_CRC("InspectorTestService2"));
         }
 
-        virtual ~Inspector_TestComponent2() override
+        ~Inspector_TestComponent2() override
         {
         }
 
@@ -205,7 +205,7 @@ namespace UnitTest
             services.push_back(AZ_CRC("InspectorTestService3"));
         }
 
-        virtual ~Inspector_TestComponent3() override
+        ~Inspector_TestComponent3() override
         {
         }