Vocaloid designs

BUR #36380 is pending approval.

create implication ia_(cevio_ai) -> ia_(vocaloid)
create implication ia_(cevio_ai_talk) -> ia_(vocaloid)
create implication otomachi_una_(vocaloid6_spicy) -> otomachi_una_(spicy)
create implication otomachi_una_(vocaloid6_sugar) -> otomachi_una_(sugar)
create implication luo_tianyi_(ai) -> luo_tianyi

Some Vocaloid designs I noticed we were missing tags for.

BUR #36381 is pending approval.

create alias hiyama_kiyoteru_(vocaloid4) -> hiyama_kiyoteru
create implication hiyama_kiyoteru_(rock) -> hiyama_kiyoteru
create implication hiyama_kiyoteru_(natural) -> hiyama_kiyoteru

His standard design doesn't actually change between V2 and V4. Instead he gets two new designs, Natural and Rock, which shouldn't be combined into one tag.