This makes ALP tokens unspendable.
We add a data structure to store outpoints that may be ALP tokens. For now, the detection logic is very basic: we freeze all outputs in any transaction whose first output is a valid EMPP output with at least one payload that starts with the ALP lokad ID.
A known drawback is that this method makes the change output also unspendable (for users who import a seed from a token wallet such as CashTab into Electrum ABC). Future improvements should be to:
- make it possible for users to force-spend SLP, ALP and false positive ALP outputs if they insist
- properly parse ALP tokens to eliminate these known false positives