[Task]
- Mouse click-driven caret movement is now handled in WebGLInput::Update
    - Input/textarea caret position <= InputField caret position
    - Modified style to prevent input/textarea from being clickable
    - Commented out DeactivateInputField of Blur coroutine
        to prevent focus out -> focus in when clicking the InputField again
- Keyboard input-driven caret movement is now handled in WebGLInput::OnValueChange
    - InputField caret position <= input/textarea caret position
- Created KeyboardDownHandler for actions like Ctrl, Shift, arrow keys, etc