NFT parent token do not get burned immediately upon child genesis.

[mainnet-pat]

Hi, I've seemingly discovered a bug in SLPDB. When doing an NFT child genesis SLPDB does not check for parent token burns until a new block arrives. This results in the queries to SlpServe to return stale results about parent token amounts and lead to a double spend attempts.

On my regtest node I do following:

1. Create a parent token with the quantity 1
2. Ask slpdb about the parent token to prepare the input
3. Create child token by spending the parent token as BCH
4. Ask slpdb about the parent token to check it was burned

Steps 2 and 4 yield the same result from graph database. Unless there is a block mined between 3. and 4, then I see burnSearch-xxx in the SLPDB logs and graphItemsUpsert updates the graph db.

pat.