fix issue from tobias #9

Old, should happen on develop Tobias:

• Add all C2 models
• Spring
• only mean / median visible
• filter location to NH polar region => plot is gone (because the values are not automatically adjusted

I fixed this issue.

Additonally, I removed the toolbar from both plots:

• for the tco3_return only the download options were available, this should be done via our download modal
• for the tco3_zm same applies to the download options. The manual zoom is also disabled because if was buggy i.e. we cannot detect the zooming => the markers on the y-axis and the x-axis were gone and the graph changed its width. => download and zooming should be done with our provided sidebar