fdo#60698: Merge all libs of io...

creating the libio. All these libraries are always used together, so we can put them
together in one single library.

This save almost 500 kb of the size of the final library.

Change-Id: Ib32fec36cc4eb80ca646ce472c1f1bcdd98ac62b
Reviewed-on: https://gerrit.libreoffice.org/6567
Tested-by: LibreOffice gerrit bot <gerrit@libreoffice.org>
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
Tested-by: Stephan Bergmann <sbergman@redhat.com>