92993aa5cf Change SignTransaction's input_errors to use bilingual_str (Andrew Chow)
171366e89b Use bilingual_str for address fetching functions (Andrew Chow)
9571c69b51 Add bilingual_str::clear() (Andrew Chow)
Pull request description:
In a couple of places in the wallet, errors are `std::string`. In order for these errors to be translated, change them to use `bilingual_str`.
ACKs for top commit:
hebasto:
re-ACK 92993aa5cf, only rebased since my [previous](https://github.com/bitcoin/bitcoin/pull/22337#pullrequestreview-694542729) review, verified with
klementtan:
Code review ACK 92993aa5cf
meshcollider:
Code review ACK 92993aa5cf
Tree-SHA512: 5400e419dd87db8c49b67ed0964de2d44b58010a566ca246f2f0760ed9ef6a9b6f6df7a6adcb211b315b74c727bfe8c7d07eb5690b5922fa5828ceef4c83461f