feat(mdns): Add version keys (IDFGH-14730)

[ascillato]

Description

This PR aims to add version keys that can be retrieved from the firmware when using the mDNS component. The version keys are needed so the firmware can tell which version of the MDNS component is using. This is required when doing firmware certification under some standards, for example Measurement Canada.

This is a commit cleaned version of #769 as requested.

Thanks for your time.

Related

None.

Testing

ESP_LOGI(TAG, "mDNS Ver: %s", ESP_MDNS_VERSION_NUMBER);

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Checklist

Before submitting a Pull Request, please ensure the following:

• 🚨 This PR does not introduce breaking changes.
• All CI checks (GH Actions) pass.
• Documentation is updated as needed.
• Tests are updated or added as necessary.
• Code is well-commented, especially in complex areas.
• Git history is clean — commits are squashed to the minimum necessary.

[david-cermak]

still LGTM, but there's a formatting issue in https://github.com/espressif/esp-protocols/actions/runs/13506222535/job/37764185874?pr=772

please install the pre-commit hook and it will fix formatting for you.
PS: sorry this is unrelated to your changes, I've recently fixed astyle configs for some longer lines to be processed correctly.

[ascillato]

I have installed as your request: pip install pre-commit && pre-commit install-hooks && pre-commit install --hook-type commit-msg --hook-type pre-push

but now I can not commit anymore. It did not specify which is the error and it does not allow me to continue.

This PR was super small and shouldn't take this long. I think I will leave the PR idea for you to add if it suits your project.

Thanks for your time.

[david-cermak]

I have installed as your request: pip install pre-commit && pre-commit install-hooks && pre-commit install --hook-type commit-msg --hook-type pre-push

but now I can not commit anymore. It did not specify which is the error and it does not allow me to continue.

This PR was super small and shouldn't take this long. I think I will leave the PR idea for you to add if it suits your project.

Thanks for your time.

Sorry to hear it, contributing to espressif repos might get tricky. Would you mind sharing the error message you're experiencing and the platform you're on? Maybe we can help and maybe we could make the process less cumbersome?

Anyway, I'm taking your commits to #773 and planning on accepting and publishing the changes (this exact commit, so it'd be still attributed to you)
Thanks again for the contribution!