Adjust color picker window height if it doesn't fit on screen (#113)

* Restrict the Color Picker's Height and add vertical scrollbar if the user's Screen Resolution is too small.

* Resize Window instead of adding Scrollbar.
Solution provided by Sonicflare

* small tweak to undo an unintended change

* Fixed indentation of xaml
Keep aspect ratio when resizing window

* Fix indentation of xaml

Author: CWO333