Optimize autoloader level 2

[CarlSchwan]

This is using the APCu cache approache since because we load dynamically
other apps that don't include a composer autoloader file the authoritative
class maps approach is not possible.

See
https://getcomposer.org/doc/articles/autoloader-optimization.md#optimization-level-2-b-apcu-cache

Test plan:

1. Enable it
2. Browse a few pages, nothing unusual happens

[kesselb]

Please check #11290 / #11292

[CarlSchwan]

Please check #11290 / #11292

Thanks for the links, i guess if this was a so easy fix someone else would have already done it. I will see if I can fix it otherwise I will close this Pr

[kesselb]

Thanks for the links, i guess if this was a so easy fix someone else would have already done it.

Hmm. Also possible that everyone just forget about it ;) To invalidate the apcu cache properly some identifier is needed that changes when server and/or apps are updated.

[CarlSchwan]

Thanks for the links, i guess if this was a so easy fix someone else would have already done it.

Hmm. Also possible that everyone just forget about it ;) To invalidate the apcu cache properly some identifier is needed that changes when server and/or apps are updated.

Alternatively we could also clear the apcu cache after an update or an app is enabled/disabled