Restructure user interface

User story 1: A user selects "line chart" chart type from a drop down list. The user is then presented with an option for creating a chart that compares two similar sensors e.g. compare Vorlauftemperatur for Buildings 105 and 225.

User story 2: A user selects "scatterplot" chart type from a drop down list. The user is then presented with an option for creating a chart that compares two different sensors e.g. Vorlauftemperatur & Außentemperatur, Power & Rücklauftemperatur, Power & Vorlauftemperatur.