Update Legends to new KQuickCharts API
This removes usage of some things that were deprecated in KQuickCharts. It also ports the Text face to use Quick Charts Legend internally so it gains the multi-column features from the new Legend. Additionally, it contains a method to get the maximum width of a unit using a certain font. This is used to calculate the maximum size of sensor values so we avoid changing the value widths.
Edited by Arjen Hiemstra