Add faction statistics

[alecsci]

• before working on this issue, finish: Find better alternative for amCharts4 #22
• show horde / alliance number of players
• no need for extra data from server api
• must be in the same chart page (?)
• allign correctly with the other charts
• suggested from: Find more useful statistics to be shown  #4

[Helias]

must be in the same chart page (?) -> I think so