We introduce Taproot support in the test framework through a global
toggle. A few modifications are made to some tests to adapt them under
Taproot (notably the hardcoded fees / amounts).
This is based on my introduction of a quick and dirty support for
TapMiniscript in my python-bip380 library:
https://github.com/darosior/python-bip380/pull/23. In addition to this i
didn't want to implement a signer in the Python test suite so here we
introduce a simple Rust program based on our "hot signer" which will
sign a PSBT with an xpriv provided through its stdin and output the
signed PSBT on its stdout. Eventually it would be nicer to have a Python
signer instead of having to call a program.
The whole test suite should pass under both Taproot and P2WSH. Only a
single test is skipped for now under Taproot since it needs a finalizer
in the test suite.
I also caught a bug in the RBF tests which i fixed in place.
This adds a new utils function that is a slight generalisation
of `wait_for` with an additional condition that must always be
met while waiting.
`wait_for` now calls this new function with the condition being
one that is always true.
The outpoints argument could eventually be made optional in order to
introduce some automated coin selection. So it makes more sense for it
to be after a required parameter, the destinations.
This replaces our existing implementation of PSBTs with a more
straightforward one, adapted from the Bitcoin Core functional tests
framework. This fixes a few flakes that occured because the previous
implementation could produce invalid PSBTs.
The Bitcoin Core implementation is pretty low level and was adapted to
treat mappings as such (the value in the PSBTMap can itself be a
mapping, like for partial signatures or BIP32 derivation paths).
The rest of the diff is adapting the users of PSBT to use the new
implementation and the clearly superior interface (yay!).
