deduplicate meta tag records when returning from meta tag hierarchy
deduplicate meta tag records when returning from meta tag hierarchy

raintank/raintank-metric,raintank/metrictank,raintank/raintank-metric,replay/metrictank,raintank/metrictank,replay/metrictank,raintank/metrictank,raintank/raintank-metric,raintank/metrictank,replay/metrictank,replay/metrictank