[Post -0.21] Runing createwallet on a node should anyonecanspendismine it should rescan by default

With initialfreecoins and anyonecanspend in elements.conf, we should rescan the wallets for looking for anyonecanspend outputs.

Pre 0.21, this is not an issue because whenever the default wallet was created, it autoscanned the blockchain looking for anyonecanspend outputs. But since 0.21, there is no default wallet creation and using createwallet does not scan the blockchain for anyonecanspend outputs.

initialfreecoins=2100000000000000
anyonecanspendaremine=1

Quick fix: After creating a wallet with createwallet, in order to scan anyonecanspends run either importprivkey <any_key>(tested) and ``rescanblockchain or(should work, but not tested).

If this is annoying/unergonomic to fix, we should at least update the documentation about this behavior. Notably, our tutorials from https://elementsproject.org/elements-code-tutorial/basic-operations won't work.

Commencez par le RPC createwallet et comparez son comportement avec le chemin de création du portefeuille par défaut antérieur à 0.21. Utilisez les paramètres initialfreecoins et anyonecanspendaremine, puis vérifiez si les sorties anyonecanspend sont trouvées sans le contournement importprivkey et rescanblockchain. C’est terminé lorsque le nouveau portefeuille effectue une nouvelle analyse par défaut, ou lorsque le tutoriel documenté et le comportement correspondent clairement.