lock-collection logic needs fixed

[bmacer]

lock collection sets max to currently-minted. so someone could then burn and re-mint, which doesn't lock.
perhaps set max to one less than the currently-minted, then add a check when burning so if currently_minted < max (and not zero) then burning is not allowed.

[HashWarlock]

Correct me if I'm misinterpreting this, but we wouldn't decrement the amount of minted NFTs when we burn an NFT within a collection, right? At least that is what I ran into with RMRK 1.0 Collections before. Burning would only destroy the NFT, but the NFTs minted in the collection count would remain the same.

So in this case would it make sense to check the NextNftId value be a way to determine if we have hit the max value? For example, I minted an NFT in a collection and Burn that NFT, but the NextNftId returns 1:

Then I go and mint a new NFT which would have 1 active NFT in the collection, but the NextNftId will still increment to 2 seen here:

This would make it where if we were to check the NextNftId and compare that to the collection's max value then if they are equal, we would not perform the minting of a new NFT.