fix the pseudopotential bugs

[dou-du]

The following bugs have been fixed:

• replace set_data(x,y) with set_data([x],[y])
• the clear method is not working anymore with matplotlib

for line in ax.collections:
      line.remove()

• When moving the Rc, the horizontal line x=0 is disappeared. Fix it with replace the line.

[github-actions]

👈 Launch a Binder on branch osscar-org/quantum-mechanics/pseudopotential