feat(unstable): --allow-net subdomain wildcards

[nayeemrmn]

Closes #6532.

// deno run --unstable-subdomain-wildcards --allow-net=*.github-proxy.voidd.workers.dev main.ts

await fetch("https://foo.github.com");

Supports one wildcard which must be the first label. Doesn't support wildcards in a middle label like cloudformation.*.amazonaws.com as one user requested. Based on https://developers.cloudflare.com/dns/manage-dns-records/reference/wildcard-dns-records/#aspects-to-consider.

https only
deno run --allow-net=https://* server.js
or
deno run --allow-net=*/**:443 server.js

Let's decline these ones.

[Hajime-san]

IMO, users may need to be concerned about attacks via dangling records, while this feature is safe to use in most cases.

https://www.form3.tech/blog/engineering/dangling-danger
https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/protection-from-dangling-dns.html