Some additional Windows 10 styles

Like this (hope it helps):

Most changes would be a slightly thicker border / different arrow.

[x] Flat button:

[x] Radio button:


[x] Checkbox:


Combobox:


Textbox:


Scrollbar:


I might've forgotten a few, if an image/gif needs to be added, feel free to ask.

No files, tests, or entry points are named. Start by locating the existing Windows 10 control styles, then compare the flat button, radio button, checkbox, combobox, textbox, and scrollbar against the supplied images; the work is done when the requested border and arrow differences are implemented consistently.

Written by the indexing model from the issue text.