Conflicting services in postoffice_twig and postoffice_image

Problem/Motivation

Both modules Postoffice Twig and Postoffice Image each declare a service with the name twig.extension.postoffice. If both extensions are active, they will silently override each other.

Steps to reproduce

Enable Postoffice Twig and Postoffice Image, then try to use twig functions / filters from both of them.

Proposed resolution

Use unique service names.

Remaining tasks

User interface changes

API changes

Data model changes