```
Not sure why all these includes were missing, but it's breaking builds
for some users:
https://bugs.gentoo.org/show_bug.cgi?id=652142
(Added to all files with a reference to std::unique_ptr)
```
Backport of core PR12859:
https://github.com/bitcoin/bitcoin/pull/12859/files
This has been heavily adapted to our codebase.
I grepped all the units (.h and .cpp) including `memory`, the ones using
`std_unique_ptr` and used the diff to track down the needed inclusions.
Depends on D4588.