Bugfix: f orbitals in the oct_ylm routine.

Description

Add the missing support of f electrons in the ylmr routine. This affect LCAO and DFT+U parts of the code.

News snippet

Add the missing support of f electrons in the ylmr routine.

Checklist

• I have checked that my code follows the Octopus coding standards
• I have added tests for all the new features added in this request.