Fix namespace and class names for various test cases (take#4)

Important Note: the HEAD in the commands below assume that the branches have been integrated without any merge commit. You may need to replace them by the real commits if the issue has been integrated with merge commit. Here there are the commit details:

• 311_STABLE:
  • HEAD = 61cedbd56e68eb785ee26f2c744e0732c70eb258
• 400_STABLE
  • HEAD = 5c884e835ef1315bf9da29c516be3cf27907bba0
• master:
  • HEAD = 83b490a5947642a3f6e73520402bb5e63edf8022

A) General

1. Verify that complete PHPUnit runs are passing (GHA, ToBiC...) for all branches.

B) Testing instructions for 311, 400 and master

1. Install local_codechecker in the site.
2. Run this (see the important note above about the HEAD alternatives and commits):

   git show --pretty="" --name-only HEAD | \

   xargs local/codechecker/phpcs/bin/phpcs --standard=moodle --extensions=php \

   --sniffs=moodle.PHPUnit.TestCaseNames,moodle.Files.MoodleInternal -p \

   && echo "Yay"

3. Verify that you get 125 dots in the output, without any error and with "Yay" printed at the end.
4. Init phpunit: php admin/tool/phpunit/cli/init.php
5. Run this (see the important note above about the HEAD alternatives and commits):

   git show --pretty="" --name-only HEAD | \

   xargs -n 1 -I {} bash -c "echo {}; vendor/bin/phpunit {} > /dev/null || echo ERROR"

6. Verify that you don't get any "ERROR" output, that means that all the tests modified can be run individually.
   • Note: if you get an ERROR on lib/tests/environment_test.php it means you need to enable and increase your max_input_vars to 5000, for more information see this doc page
7. Run this (see the important note above about the HEAD alternatives and commits):

   git show --pretty="" --name-only HEAD | \

   grep -v '/tests/.*_test.php'

8. Verify that no files are returned.