Change Details

``` Refactor the new CombinePSBT, FinalizePSBT, and FinalizeAndExtractPSBT general-purpose functions out of the combinepsbt and finalizepsbt RPCs, for use in the GUI code. ``` Completes backport of core PR14978: https://github.com/bitcoin/bitcoin/pull/14978/commits/102faad81efa1cb12c29c466cfe81fc8c7351e1d Depends on D5739.

``` Refactor the new CombinePSBT, FinalizePSBT, and FinalizeAndExtractPSBT general-purpose functions out of the combinepsbt and finalizepsbt RPCs, for use in the GUI code. ``` Completes backport of core [[https://github.com/bitcoin/bitcoin/pull/14978 | PR14978]]: https://github.com/bitcoin/bitcoin/pull/14978/commits/102faad81efa1cb12c29c466cfe81fc8c7351e1d Depends on D5739.

``` Refactor the new CombinePSBT, FinalizePSBT, and FinalizeAndExtractPSBT general-purpose functions out of the combinepsbt and finalizepsbt RPCs, for use in the GUI code. ``` Completes backport of core [[https://github.com/bitcoin/bitcoin/pull/14978 | PR14978:]]: https://github.com/bitcoin/bitcoin/pull/14978/commits/102faad81efa1cb12c29c466cfe81fc8c7351e1d Depends on D5739.