qemu: command: move NUMA validation to qemu_domain.c

qemu: command: move NUMA validation to qemu_domain.c

A new qemuDomainDefValidateNuma() function was created to host
all the QEMU caps validation being done inside qemuBuildNumaArgStr().
This new function is called by qemuDomainValidateCpuCount()
to allow NUMA validation in domain define time.

Tests were changed to account for the QEMU capabilities
that need to be present at domain define time.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>