refactor: Error message bilingual_str consistency

- Move the decision whether to translate an error message to where it is
  defined. This simplifies call sites: no more `InitError(Untranslated(...))`.

- Make all functions in `util/error.h` consistently return a
  `bilingual_str`. We've decided to use this as error message type so
  let's roll with it.

This has no functional changes: no messages are changed, no new
translation messages are defined.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/util/error.h b/src/util/error.h
index 61af88ddea..b9830c9eea 100644
--- a/src/util/error.h
+++ b/src/util/error.h
@@ -32,9 +32,9 @@ enum class TransactionError {
     MAX_FEE_EXCEEDED,
 };
 
-std::string TransactionErrorString(const TransactionError error);
+bilingual_str TransactionErrorString(const TransactionError error);
 
-std::string ResolveErrMsg(const std::string& optname, const std::string& strBind);
+bilingual_str ResolveErrMsg(const std::string& optname, const std::string& strBind);
 
 bilingual_str AmountHighWarn(const std::string& optname);