Change Details

This is a partial backport of [[https://github.com/bitcoin/bitcoin/pull/25254 | core#25254]] The other unrelated changes related to includes are debatable and can be done in a separate diff if we want them. Also the iwyu tool used by Core to lint these includes seems very finicky, I'm not sure it is worth the effort to port it for now. I just checked that all files using `DEFAULT_MIN_RELAY_TX_FEE` include `policy/policy.h` and all files using `minrelaytxfee` include `policy/settings.h` Depends on D14888

This is a partial backport of [[https://github.com/bitcoin/bitcoin/pull/25254 | core#25254]] The other unrelated headers changes are debatable and can be done in a separate diff if we want them. Also the iwyu tool used by Core to lint these includes seems very finicky, I'm not sure it is worth the effort to port it for now. I just checked that all files using `DEFAULT_MIN_RELAY_TX_FEE` include `policy/policy.h` and all files using `minrelaytxfee` include `policy/settings.h` Depends on D14888

This is a partial backport of [[https://github.com/bitcoin/bitcoin/pull/25254 | core#25254]] The other unrelated changes related to includesheaders changes are debatable and can be done in a separate diff if we want them. Also the iwyu tool used by Core to lint these includes seems very finicky, I'm not sure it is worth the effort to port it for now. I just checked that all files using `DEFAULT_MIN_RELAY_TX_FEE` include `policy/policy.h` and all files using `minrelaytxfee` include `policy/settings.h` Depends on D14888