Implement invalid-parameters-error in LSPS1 / LSPS2

[tnull]

When we dropped versioning support a new error type was introduced: invalid-parameters-error (see https://github.com/BitcoinAndLightningLayerSpecs/lsp/tree/main/LSPS0#-32602-invalid-parameters-error).

We currently don't return it, but should, at least if it's not too cumbersome.

Other implementors before mentioned that it's not trivial to do with serde, if it's too cumbersome we might want to bring it back to the spec group.