payload asset: call mint before setUri

[asooge]

• when initialize payload asset call mint before setUri to be consistent with spaceible asset: https://github.com/copernicspace/core/blob/master/contracts/spacemart/payload/PayloadAsset.sol#L53

the reason is the subgraph indexes events in sequence and expects asset to exist in order to set the uri and metadata properties. Asset does not exist until mint calls handleTransferSingle