feat(auth): improve redis command parsing and validation

[savonarola]

Fixes EMQX-10193

Summary

🤖 Generated by Copilot at 2fa717c

This pull request improves the Redis plugin for EMQX by adding a new module emqx_redis_command for parsing and validating Redis commands, using this module in the authentication and authorization backends, and adding more tests and validations for the Redis plugin. It also fixes some typos and inconsistencies in the code.

PR Checklist

Please convert it to a draft if any of the following conditions are not met. Reviewers may skip over until all the items are checked:

• Added tests for the changes
• Added property-based tests for code which performs user input validation
• Changed lines covered in coverage report
• Change log has been added to changes/(ce|ee)/(feat|perf|fix)-<PR-id>.en.md files
• For internal contributor: there is a jira ticket to track this change
• Created PR to emqx-docs if documentation update is required, or link to a follow-up jira ticket
• Schema changes are backward compatible