LPS-51846 add extension to content ref
LPS-51846 inline and reorder validations
LPS-51846 create file name/ext validators
LPS-51846 remove hardcoded validations
LPS-51846 inject all validations into DM repo
LPS-51846 SF
LPS-51846 rename, I found DLFile confusing.. is it a DLFileEntry ,a FileEntry, or a DLFileVersion etc? If it's going to be used outside of the liferay impl, I would rename it to FileEntryModelValidator and not DLFileEntryValidator since that is for the internal impl