Better visualization of trashcan graphs

[PaulaScharf]

Currently values in the graph have a fixed horizontal distance between each other, no matter the time that has passed. This should be changed, so that time on the x-axis increases continuously.

Example of the issue:

[PaulaScharf]

also open to other suggestions for better visualization. Like maybe we can do sth about the scrollbar? Maybe if you hover over the graph and scroll with the mouse wheel the graph moves from side to side