'Switch to next phase' should skip Grading evaluation phase when hidden

When  in a workshop submissions and assessments are not graded, the  'Grading evaluation phase'  is unset and does not display. Therefore, 'Switch to next phase' link should respect this condition and skip the this phase.

After creating the MDL, I realised that the unset of the 'Grading evaluation phase' is done as an override of

render_workshop_user_plan() in our theme, subsequently, the changes for 'Switch to next phase' link, will be implemented in the same overridden function.

In other words, this is not an issue for Moodle core workshop.