testQemuGetLatestCaps: Process capabilities for all architectures in one pass

testQemuGetLatestCaps: Process capabilities for all architectures in one pass

Rather than finding the newest caps file iteratively for specific
architectures in multiple passes over the directory we can simply load
the latest for everything in one pass by storing the version in the hash
table and filling it progressively.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>