(feat) allow setting --host-resolver-rules

[timkent]

I wanted to use this tool to test some reverse proxies that use split DNS, so I can't assume that the DNS host is available or pointing to the correct place.

To do this I have added a --chrome-host-resolver-rules option that passes through to the Chrome --host-resolver-rules option. The format of the rules are explained here:
https://chromium.googlesource.com/chromium/src/+/HEAD/net/dns/mapped_host_resolver.h#40

Here is an example where it is sending my request for http://example.com to 127.0.0.1:8000 and https://example.com to 127.0.0.1:8443 using the one rule:

# gowitness scan --chrome-host-resolver-rules "MAP example.com:80 127.0.0.1:8000,MAP example.com:443 127.0.0.1:8443" single -u http://example.com
# gowitness scan --chrome-host-resolver-rules "MAP example.com:80 127.0.0.1:8000,MAP example.com:443 127.0.0.1:8443" single -u https://example.com

I did some limited testing and Chrome appears to be sending the correct host header and SNI.

Thank you for this awesome project!