NC | Fix test_nc_upgrade_manager cleanup

[romayalon]

Explain the changes

1. Fixed a bug in the mode of some paths created during the test - changed permissions from 777 to 0o777.
2. Changed to the 0.0.9 nc upgrade scripts directory a '0.0.9-test-nc-upgrade-manager' so it'll be extra understood this is not a real nc_upgrade_scripts dir but a mock dir for tests.
3. Added a missing call to await fs_utils.folder_delete(default_upgrade_script_dir_version_path); in order to clean-up /Users/{user_name}/github/noobaa-core/src/upgrade/nc_upgrade_scripts/0.0.9-test-nc-upgrade-manager.

Issues: Fixed #xxx / Gap #xxx

1. Fixed partially NC | Online upgrade improvements #8586

Testing Instructions:

1. Run -

sudo jest --testRegex=jest_tests/test_nc_upgrade_manager.test.js --t "nc upgrade manager - _run_nc_upgrade_scripts` 
sudo ls -la  /Users/{user_name}/github/noobaa-core/src/upgrade/nc_upgrade_scripts/

Check that /Users/{user_name}/github/noobaa-core/src/upgrade/nc_upgrade_scripts/0.0.9-test-nc-upgrade-manager does not exist.

• Doc added/updated
• Tests added

[shirady]

LGTM