refactor(errors): massaging validation messages before we assign it (#25452)

lib/config/migrations/custom/host-rules-migration.ts

lib/config/secrets.ts

lib/util/git/error.ts

lib/util/git/index.ts

lib/util/package-rules/index.spec.ts

lib/util/package-rules/merge-confidence.ts

lib/workers/repository/error-config.spec.ts

lib/workers/repository/error-config.ts

lib/workers/repository/init/merge.ts

lib/workers/repository/process/index.ts