Make the handling of unprefixed names (of labels, annotations and
extended resources) well-defined and predictable. Previously the
resulting output was not predictable in case the same name was coming in
both the unprefixed and prefixed form, say unprefixed "foo=bar" coming from
one source (be it nfd-worker or NodeFeature(Rule)) and
"feature.node.kubernetes.io/foo=baz" from a NodeFeature(Rule).
Previously the output value was randomly either "bar" or "baz".
This patch adds prefixes to all names early in the processing
"pipeline", preventing random name clashes later on.
