fix(mdns): Fix _mdns_append_fqdn excessive stack usage (IDFGH-14506)

[andrew-lifx]

Move "mdns_name_t name" declaration inside loop to move it out of scope and reclain stack space before recursion call.

Description

Move "mdns_name_t name" declaration inside loop to move it out of scope and reclaim stack space before the recursion call.

Related

Fixes #738

Testing

Tested using patched version on product build. Original was triggering a stack overflow. Stack overflow did not occur with patched version.

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.

[CLAassistant]

All committers have signed the CLA.

[david-cermak]

Thanks for the PR!

All is good, just need to click through the CLA agreement in #744 (comment)