HPCC-9595 Implement generalized paging/cache for DFU files

Previous merge broke build

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>
Merge pull request #5447 from richardkchapman/build-break

HPCC-9595 Implement generalized paging/cache for DFU files

Reviewed-By: Kevin Wang <kevin.wang@lexisnexis.com>