Allowlist checking already uses hosts but for some reason
requests, revokes and the runtime permissions API use URLs.
- BREAKING(lib.deno.unstable.d.ts): Change
NetPermissionDescriptor::url to NetPermissionDescriptor::host
- fix(runtime/permissions): Don't add whole URLs to the
allowlist on request
- fix(runtime/permissions): Harden strength semantics:
({ name: "net", host: "127.0.0.1" } is stronger than
{ name: "net", host: "127.0.0.1:8000" }) for blocklisting
- refactor(runtime/permissions): Use tuples for hosts, make
the host optional in Permissions::{query_net, request_net, revoke_net}()
