Use empty space after closing sidebar

[MichaelScheiderer]

User story

1. As a salesperson
2. I want to be able to use the empty space on the screen after closing the sidebar
3. So that I have a bigger screen to work on

Acceptance criteria

• After pressing the close-Button ("X") on the sidebar, the whole content of the website is moved to the left, so that the empty space can also be used
• The dark top bar is extended to the left, and also the text on it is moved to the left
• The button to open the sidebar is moved in the upper left corner, before of the text
• The color of the button is changed, so that its visible on the dark bar

Definition of done

• Documentation for the feature is done
• Feature branch has been merged
• Code has been reviewed by at least one other team member
• Unit tests are written