Feature: #56726 - Trigger metadata extraction after file upload

See Issue #56726

Description

Before #56726 the metadata extraction was only called through the extract metadata scheduler task. So when a editor uploaded a new file he had to wait until the scheduler task had been triggered again and extracted the metadata.

Now the metadata extraction is by default triggered after adding/uploading a file in the BE or when the FAL API is used ResourceStorage::addFile(), ResourceStorage::replaceFile() and ResourceStorage::addUploadedFile().

In some special situations it isn’t desired to have metadata extraction direct after file upload/adding a file to the storage. For these cases the automatic extraction can be disabled in File Storage configuration.

Impact

The flag is by default set for all existing and a new storage. When you have some special use-case where automatic extraction of metadata is not desired the flag can be disabled in File Storage configuration.