numatune: unify numatune struct and enum names

numatune: unify numatune struct and enum names

Since there was already public virDomainNumatune*, I changed the
private virNumaTune to match the same, so all the uses are unified and
public API is kept:

s/vir\(Domain\)\?Numa[tT]une/virDomainNumatune/g

then shrunk long lines, and mainly functions, that were created after
that:

sed -i 's/virDomainNumatuneMemPlacementMode/virDomainNumatunePlacement/g'

And to cope with the enum name, I haad to change the constants as
well:

s/VIR_NUMA_TUNE_MEM_PLACEMENT_MODE/VIR_DOMAIN_NUMATUNE_PLACEMENT/g

Last thing I did was at least a little shortening of already long
name:

s/virDomainNumatuneDef/virDomainNumatune/g

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>