This is a backport of [[https://github.com/bitcoin/bitcoin/pull/17984 | core#17984]]
Most of the PR is not relevant for us (segwit stuff or codestyle), soBackport note:
- Most of the PR is not relevant for us (segwit stuff or codestyle), so this includes only the commit that adds a useful new test for forcerelay permission.
forcerelay permission- The code to build the transaction is different because Core uses some kind of dark magic to make a transaction that does not require a signature. I used a normal address and signed it, instead.