This is a follow-up of MDL-79726, a new method was introduced to calculate the overall completion status of an activity in LMS to address an existing issue, however, the solution is not compatible with external system as this additional information is not available for them.

I think that in order to solve this and maintain external functions definitions compatibility we'll have to:

1. For 4.3 - Override the completion_info_exporter::state field and set it to just COMPLETION_COMPLETE if is_overall_complete() returned true
2. For 4.4 onward - Return a new field "overallcompletion" set to the result of is_overall_complete that will take precedence over "state" in external systems

Note for integrators: overallstatus has been removed from the exporter because it was an unused duplicated value not being exported, clearly a bug.