As per core_completion\manager::get_available_completion_tabs() the
required capability for this feature is moodle/course:manageactivities,
not moodle/course:update.

The expected size of icons in the pix/b/ (big) folder was not respected
and they were displayed as 16x16 px.

Found by the integrator review:
- Some incorrect code style declaration and phpdocs
- Missing $USER declaration
- Incorrect use of $lesson (should be $this)

There were a couple of fields missing when returning the complete
answer information required for offline usage.

Otherwise it will break the Web Service return description.

process_eol_page expects a string, right now we are passing a boolean.
We should convert it to the correct string when is set to true, that is
‘normal’

We need this field always to be able to display if the lesson is
available or not for download

Deep in the lesson API there are some http redirections in special
pages like clusters.
We need to handle it via new parameters to avoid redirections.