[Lazarus] TShiftState "lock" states in mousewheel events

[Alexander Klenin]

The TShiftState enum in LCL includes ssNum, ssCaps and ssScroll elements,
which should indicate the state of NumLock, CapsLock and ScrollLock
correspondingly.

However under Win32 KeyDown/Up and MoudeUp/Down/Move events do not
recieve these elements, while MouseWheel events do.
This required a workaround at least for TAChart:
https://github.com/graemeg/lazarus/commit/1b2369b24de952d5ef250f3a4be7607d66d55da7#L0R710

Delphi does not have these elements, and, since they are usually not
working anyway,
I suggest to remove them.

-- 
Alexander S. Klenin