730409eb5299724cdbe1a4da06d272098a791621 descriptors: prevent using a signer more than once in a single path (Antoine Poinsot)
0a95266cce618f83782d3d30362cb2d383b659bf qa: don't use a static dummy origin for descriptor xpubs (Antoine Poinsot)
Pull request description:
This is necessary to support signers which sign for a single key at once. It also doesn't make any sense to reuse a signer within the same spending path, so rule it out before it creates any new edge cases.
For more about the Bitbox signer support, which motivated this change, see
https://github.com/wizardsardine/liana/pull/706#issuecomment-1744705808.
ACKs for top commit:
edouardparis:
ACK 730409eb5299724cdbe1a4da06d272098a791621
Tree-SHA512: 3fb34f2a85e103ca5f8eeec901c283c649636971f7730743af24b270626a7fdf11f207a8f3535c9ff69ce475f34c69472595219ac97b8cfd5749379c4213a6e5