Added `IWindowEventHandler` header and class with the same name + bunch of virtual methods
Included "windows/WindowEvents" header;
All methods of IEventHandle interface now takes specified const reference to `WindowEvent::*` class
Included `windows/WindowEvents` header;
Renamed `WindowEventsPoller::"pollEvents"` to `poll`
renamed `IEventHandler` to `IWindowEventHandler`;
All methods of `IWindowEventHandler` interface are now public
Included `windows/IWindowEventHandler` instead of `windows/WindowEvents`;
`Window`class now extends `IWindowEventHandler`
Gah, compiler said that i have to merge classes declarations and definitions :C thats really sad actually
In `WindowEventsPoller`:
  - Added private `callWindowEvent` method, which takes two arguments:
      1. const reference to `WindowEvent`
      2. window id (as `uint32_t`)
Added definition of `WindowEvent::event` method
Added `WindowEventsPoller::callWindowEvent` definition, which:
  - makes an reference to chosen window;
  - by switch based on `WindowEvent::Type` calls required event-handling-method
(*
  note.1: I'll use these types of in-commits comments
  note.2: I don't this way of implementing this, but i don't see other ways :C
*)
Added virtual `IWindowEcentHandler::onMoved` method
Well, just fixed this -
I used the wrong name. In addition, missing several events.
Copy-paste method failed;
Accordingly renamed method calls + added one for `WindowEent::Type::Closed`