Fixes CORS for meshtasticd to allow use of clients on other origins

[liamcottle]

I am receiving 404 Not Found when clients using @meshtastic/js in a web browser make an OPTIONS request to /api/v1/toradio and /api/v1/fromradio on a meshtasticd node when using a custom client on another origin.

This results in not being able to communicate with the node.

#5386 fixed this when connecting to the built in ESP32 server over WiFi, this PR fixes the same thing but for the meshtasticd server as well :)

It seems there was already checks for the options requests, but they wouldn't ever be hit since only GET and POST handlers were registered.

I also changed the http_verb comparison to use strcmp as the == check never passed.

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