The zip specification states that when 'bit 3' of the general purpose
flags is set then a data descriptor record must be present. Prior to
this commit, our `VirtualZipDataBlock` ignored such records and would
create invalid data.
Although the generated data would work for zip parsers that read the
central directory records, it causes problems with streaming reader
implementations such as `JarInputStream`.
This commit updates the code so that it now copies the data descriptor
records. It support both blocks that have a signature and those that
don't. It also updates the generation logic to correctly deal with
any extra data bytes present after the local file header record.
Fixes gh-38063
bba323ba5f