Support running configuration synchronization on extension code update

Problem/Motivation

Currently, a typical use of Configuration Synchronizer is to run a site-wide update of all installed configuration. In some use cases, it might be preferable to have configuration updates apply programmatically when the version of an extension is updated.

Proposed resolution

Implement a Composer script subscribing to the post-package-update event. If the package is an already-installed Drupal extension, run config synchronization for that extension.

Remaining tasks

User interface changes

API changes

Data model changes