Add optional EMQX MQ configuration setting before installation

[sim-san]

✍️ Description

In this PR, I am adding a pre-installation prompt that allows users to enable or disable EMQX MQ functionality before container creation. This addresses a configuration requirement documented in the upstream EMQX issue.

Key Changes

• Updated resource requirements: HDD 4 -> 6 GB
• Added emqx_mq_setting() function to prompt user for EMQX MQ configuration
• Export EMQX_MQ__ENABLE environment variable (true/false) based on user selection

🔗 Related Issue

Fixes emqx/emqx#16649
See: emqx/emqx#16649 (comment)

✅ Prerequisites (X in brackets)

• Self-review completed – Code follows project standards.
• Tested thoroughly – Changes work as expected.
• No security risks – No hardcoded secrets, unnecessary privilege escalations, or permission issues.

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🛠️ Type of Change (X in brackets)

• 🐞 Bug fix – Resolves an issue without breaking functionality.
• ✨ New feature – Adds new, non-breaking functionality.
• 💥 Breaking change – Alters existing functionality in a way that may require updates.
• 🆕 New script – A fully functional and tested script or script set.
• 🌍 Website update – Changes to website-related JSON files or metadata.
• 🔧 Refactoring / Code Cleanup – Improves readability or maintainability without changing functionality.
• 📝 Documentation update – Changes to README, AppName.md, CONTRIBUTING.md, or other docs.

[MickLesk]

This will Always run before the Script Run, Update and Install.

What make this Feature?

Why Not Just an read -rp in Install?

[michelroegl-brunner]

As Mick already stated, this belongs in the emqx-install.sh file, and then just do a read for that, like we have in all other apps.

[sim-san]

Ok, will do