fix(Memcache): ensure global prefix depends on enabled apps

[susnux]

Summary

• ensure the prefix is changed when an app is (dis)enabled
• ensure the app ids are included in the hash instead of only the version numbers
• ensure hash is deterministic by always use the same order.

see also #54383 (comment)

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

[susnux]

/backport to stable32

[danxuliu]

There is still a problem with maintenance mode and cached routes even with this fix.

The global prefix is the same if the maintenance mode is enabled or disabled. However, the routes generated during maintenance mode do not seem to include apps/XXX routes. Therefore, if the route cache is generated while in maintenance mode the cache is not valid once the maintenance mode is disabled, but the same cache will be still used, thus leading to Page not found errors. Routes can be generated even while in maintenance mode due to a special handling of JavaScript files, which skip the maintenance mode and are matched even in that case, which cause the route cache to be regenerated if it was empty.

How to reproduce:

• Use a development server and ensure that no other requests than the ones below are handled
• Enable APCu cache (add 'memcache.local' => '\\OC\\Memcache\\APCu', to config.php) if not enabled already
• Enable maintenance mode (occ maintenance:mode --on)
• Reset the APCu cache (restart the web server / FPM, call apcu_clear_cache(), use https://github.com/krakjoe/apcu/blob/master/apc.php...)
• Get a JavaScript file with curl https://{YOUR_SERVER}/index.php/js/core/merged-template-prepend.js
• Disable maintenance mode (occ maintenance:mode --off)
• Get the Files apps page with curl --head https://{YOUR_SERVER}/index.php/apps/files; a 404 Not Found response is received
• Reset the APCu cache (restart the web server / FPM, call apcu_clear_cache(), use https://github.com/krakjoe/apcu/blob/master/apc.php...)
• Get the Files apps page with curl --head https://{YOUR_SERVER}/index.php/apps/files; a 401 Unauthorized response is received