4f050b91c706181084b9288b8a87b7b637e4e4f7 move-onlyish: move CCoinsViewErrorCatcher out of init.cpp (James O'Beirne)
Pull request description:
This is part of the [assumeutxo project](https://github.com/bitcoin/bitcoin/projects/11):
Parent PR: #15606
Issue: #15605
Specification: https://github.com/jamesob/assumeutxo-docs/tree/2019-04-proposal/proposal
---
This change moves `CCoinsViewErrorCatcher` out of `init` and into `coins` so that it can later be included in [a `CoinsView` instance](https://github.com/bitcoin/bitcoin/pull/15606/commits/91284964ef34b90ee6c626137973d2c15e7b25da#diff-349fbb003d5ae550a2e8fa658e475880R504) under `CChainState`.
Instead of hardcoding read failure behavior that has knowledge of qt, it accepts error callbacks via `AddReadErrCallback()`.
ACKs for top commit:
dongcarl:
re-ACK 4f050b91c706181084b9288b8a87b7b637e4e4f7
ryanofsky:
utACK 4f050b91c706181084b9288b8a87b7b637e4e4f7. Only change since last review is fixing const.
Tree-SHA512: eaba21606d15d2b8d0e3db7cec57779ce181af953db1ef4af80a0bc1dfb57923d0befde9d61b7be55c32224744f7fb6bd47d4e4c72f3ccfe6eaf0f4ae3765c17
Backport of Core PR16355