Add a `NestedFileSystemProvider` implementation so that the JDK's
`ZipFileSystem` can load content from nested jars and nested
directory entries.
Creating a `ZipFileSystem` may be a relatively expensive operation as
zip structures need to be parsed and in the case of directory entries
a virtual datablock nees to be generated on the fly. As such, we
install the `ZipFileSystem` as late as possible since in a typical
application it may never be needed.
This commit also tweaks Gradle and Maven plugins to ensure that the
service loader file is written to repackaged jars.
Closes gh-7161
