[UWP] Add style setting such as font size to preferece page

[kimitake]

• Small
• Normal
• Large
• Extra Large

Note: 950XL's display setting is 350% and it seems that the font/image size same as 8.0 versio, so the small font is too small. 820's display setting is 150% and the font/mage size is bigger than 8.0 version, and the small font is good enough, if the display setting is 125%, the small style is too small.

[kimitake]

implemented in 0.5.4.0