Add Symfony 6 support

This reverts commit cd4cb9d4.

Make getContents public to be able to use Twig templates for other things then web pages (i.e. mail templates)

Not all properties are of string type in metadata, so we need to
remove this so we can use the function for any type of language
keyed metadata item.

updated twig to version 3 and added wrapper for translation via symfony/twig-bridge

Co-authored-by: Ulrik nielsen <un@ipwsystems.dk>

Reimplement getPreferredTranslation outside of IdPDisco so it's reusable
and much more complete. The new method will search the current, default
and fallback language for a displayable string in various metadata
fields. This should be much more complete and robust than previous
approches. Make it a Twig filter so it can also be used there.

This commit consists of patches automatically generated for this project on https://scrutinizer-ci.com

Only transitive dependency remains now.

* Migrate email utils to non-static

* Migrate http utils to non-static

* Migrate net utils to non-static

* Migrate random utils to non-static

* Migrate system utils to non-static

* Migrate time utils to non-static

* Migrate xml utils to non-static

* Upgrade notes

* Update test-framework

* Fix tests

Previously, would show inappropriate precision, like "0.0598134 hours ago"
or "1490532.4129 hours from now" depending on the expiration date.

Convert to our wrapper class for assertions