www/caddy: Add support for for resolvers option for tls block

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Is your feature request related to a problem? Please describe. https://caddyserver.com/docs/caddyfile/directives/tls#resolvers

Add configuration parameter to specify the resolvers in the TLS block of caddyfile

Describe the solution you'd like Seems like this could be global option in the DNS providers tab

Describe alternatives you've considered None, this is just exposing existing caddy options to user

Additional context tls { ... resolvers 1.1.1.1 1.0.0.1 }

basically any resolvers specified in the dns providers config, would populate these in each TLS block in caddyfile

thanks

opnsense / plugins