I missed all the entry pages when converting from set_abc() and get_abc() to set('abc', ) and get('abc').
Also fixed a wrong namespace for core_competency\external\performance_helper
* Added method page_helper::setup_for_plan
* Added hook to extend navigation
* Configured navigation in the following learning plan pages:
** plans.php
** plan.php
** editplan.php (For both Adding and editing of a learning plan)