This allows a user of this class to set the ignoreMaximumSize flag in the PreviewJobs used.

Dolphin has a logic where it will always ignore the maximum size for local files (isLocalFile or protocolClass == ":local"). This doesn't work in FolderView which uses this class to generate previews for its files.

The question on the other hand is whether we should just adopt this policy globally in PreviewJob itself instead.