cli spark_conf should support relative path

Currently support abs path only and don't report the reason of load ini failure

Look for CLI code handling spark_conf loading, likely in a source file related to configuration or CLI entry points. The issue mentions supporting relative paths and improving error reporting for .ini file load failures. Start by finding where the absolute path check is made, modify to resolve relative paths, and add descriptive error messages. Test by running the CLI with a relative path to a spark configuration file.

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