Right-to-left mirroring not implemented

Currently there are severe bugs that show up when mirroring is being used such as corrupted drawing, missing text and even complete UI elements dont show up.

Mirroring can be applied in 2 methods:

1. A window can be created/set as an RTL window and then its layout and child window positions change, the child window positioning in proper mirrored positions works some times. (e.g. dialog box controls do place themselves properly).
2. A device context (DC) can be mirrored (or already mirrored if belongs to a mirrored window) and here the issues are way more noticeable.

While looking at how Wine does I have noticed that the transformation that LPtoDP uses is calculated differently, calculation that completely absent in ReactOS.

There are more things that need to be fixed I think so this can be a tracker for that.

https://docs.microsoft.com/en-us/globalization/localizability/mirroring-awareness