Complete i18n for log and exception messages

[JackieTien97]

Summary

• Replace raw log and exception message strings with locale-backed message constants across iotdb-core, selected Java client modules, and external-service-impl.
• Add matching English and Chinese i18n constants, including helper and verification-style exception messages.
• Keep message constant structures aligned between English and Chinese source sets.

Validation

• Custom i18n scan: log=0, new_exception_or_error=0, setMessage=0, super_string=0, static_message_in_exception_file=0, helper_message=0, i18n_pair_or_constant_errors=0, missing_message_refs=0.
• mvn spotless:apply -pl iotdb-core/calc-commons,iotdb-core/confignode,iotdb-core/consensus,iotdb-core/datanode,iotdb-core/metrics/core,iotdb-core/metrics/interface,iotdb-core/node-commons,iotdb-client/cli,iotdb-client/isession,iotdb-client/jdbc,iotdb-client/service-rpc,iotdb-client/session,iotdb-client/subscription,external-service-impl/mqtt,external-service-impl/rest
• git diff --check -- iotdb-core iotdb-client external-service-impl distribution
• mvn clean package -pl distribution -am -DskipTests