Create C-ICAP plugin to send requests over MQTT.

I'm interested in using C-ICAP Server to send 'domain check' requests over MQTT. The C-ICAP server will integrate with squid proxy server, all requests will be passed to the icap for checking. For example, if I visit [login to view URL] it should send a MQTT request over a topic (for example domainCheck) with data mywebsite.com. It will then wait for a response on the topic (domainResponse) which will simply have allowed or rejected. Depending on the response, the ICAP server will then give a 200 ok (with the correct content), or else will return 401 with some fake page content. The purpose is to create an offsite block/allow list. Additionally the userId (read from a file at c-icap server launch) should be sent across with the domain check request. Additionally the module as well as c-icap should be compilable for OpenWRT (this is where the c-icap server will be running). Makefile for OpenWRT should be provided.