Reorder property names in FlamingoThemesCode.ThemeClass

Since the properties of FlamingoThemesCode/ThemeClass do not follow any specific order at the moment it seems, it's a bit difficult to know where to find them when editing them in object mode. Also, a developer typically updates the LESS code quite often, so it would be handy if the position of that property could be found quickly, eg at the end.

This issue is about reordering all properties alphabetically except for LESS code which would be at the end.

https://www.xwiki.org/xwiki/bin/view/FlamingoThemesCode/ThemeClass