Allow customization of conversion to relative paths

Currently, any absolute paths of a `dataFile` is converter to relative path in the `DeltaClient`
https://github.com/onetable-io/onetable/blob/69282bd27abefc4d52c45dca33965cb93fca228a/core/src/main/java/io/onetable/delta/DeltaDataFileUpdatesExtractor.java#L104

This conversion is hardcoded as `relative paths more commonly supported by query engines`. As indicated in the comment, this conversion can be limiting for users who may want to preserve absolute paths or handle path schemes differently. It would be useful to have the ability to inject custom code and allow for customization of the path conversion process.