Fix memory issue on the student courses reports screen

[m1r0]

Resolves #7439

This PR fixes an "out of memory" error on the student courses reports screen on sites with many students.

The main issue was when checking if the current user has access to the student's report screen. For that, the code was fetching the course status for all students for all courses. To make it worse, WP_Metadata_Lazyloader tries to fetch all the comment metas at once and fills the memory of the server.

Before:

After:

Proposed Changes

• Optimize the Sensei_Teacher::get_learner_ids_for_courses_with_edit_permission method so it will fetch the needed data in a more efficient way.
• Prepare the Sensei_Teacher::get_learner_ids_for_courses_with_edit_permission method for HPPS. This method is not used on the front-end so the HPPS logic is not in use currently.
• Bypass checking for screen access permission if the current user is an admin. This skips the unnecessary call to Sensei_Teacher::get_learner_ids_for_courses_with_edit_permission for admin users.

Testing Instructions

1. Enable the WP Query plugin.
2. Go to Sensei LMS -> Reports -> Students and select a student.
3. The screen should be loading as before.
4. Notice a decrease in the memory usage on that screen compared to trunk. For me, the decrease was around 5% because my local database is not that big.
5. If you have a big database at hand, test with that.

Pre-Merge Checklist

• PR title and description contain sufficient detail and accurately describe the changes
• Acceptance criteria is met
• Decisions are publicly documented
• Adheres to coding standards (PHP, JavaScript, CSS, HTML)
• All strings are translatable (without concatenation, handles plurals)
• Follows our naming conventions (P6rkRX-4oA-p2)
• Hooks (p6rkRX-1uS-p2) and functions are documented
• New UIs are responsive and use a mobile-first approach
• New UIs match the designs
• Different user privileges (admin, teacher, subscriber) are tested as appropriate
• Legacy courses (course without blocks) are tested
• Code is tested on the minimum supported PHP and WordPress versions
• User interface changes have been tested on the latest versions of Chrome, Firefox and Safari
• "Needs Documentation" label is added if this change requires updates to documentation
• Known issues are created as new GitHub issues

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (85fdd5f) 51.20% compared to head (b86b965) 51.26%.
Report is 7 commits behind head on trunk.

❗ Current head b86b965 differs from pull request most recent head 7910c7f. Consider uploading reports for the commit 7910c7f to get more accurate results

Additional details and impacted files

@@             Coverage Diff              @@
##              trunk    #7468      +/-   ##
============================================
+ Coverage     51.20%   51.26%   +0.05%     
+ Complexity    11189    11184       -5     
============================================
  Files           614      614              
  Lines         47230    47229       -1     
  Branches        405      405              
============================================
+ Hits          24186    24211      +25     
+ Misses        22717    22691      -26     
  Partials        327      327              

Files	Coverage Δ
includes/class-sensei-analysis.php	20.94% <100.00%> (+0.19%)	⬆️
includes/class-sensei-teacher.php	53.79% <100.00%> (+3.79%)	⬆️

... and 1 file with indirect coverage changes

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[donnapep]

I didn't notice a performance improvement, but I did check that the data was still the same when logged in as an admin or as a teacher. Looking at the code, I guess this should also be tested with HPPS on and off?

[Imran92]

LGTM too 👍

[m1r0]

I guess this should also be tested with HPPS on and off?

Hm, I thought covering it with unit tests should be enough but just in case I did a few more live HPPS tests as well. I'll start adding HPPS test instructions in the future. 👍