Normalization shouldn't be the first step

**Is your feature request related to a problem? Please describe.**
When working with raw data, the first step should be filtering and then afterwards normalization. Currently, the way the website is laid out, it leads to the user first applying the normalization, then going down the list (Welcome -> Data Overview & Filtering -> ...) This is not ideal and could lead to issues when applying filtering on normalized data. Additionally, the Notification stating "Currently no normalization applied!" reinforces this issue, suggesting that it is important to do the normalization first.

**Describe the solution you'd like**
Move the normalization step below "Data Overview & Filtering"

**Describe alternatives you've considered**
Communicate to the user that, when raw data is used as input, the data should first be filtered, and then normalized (maybe add some text to the notification). For this, it would be important to first fix issue #70 regarding switching back to "no normalization".