cmd/viewer: add field comments to generated view methods

Extract field comments from AST and include them in generated view
methods. Comments are preserved from the original struct fields to
provide documentation for the view accessors.

Fixes #16958

Signed-off-by: Maisem Ali <3953239+maisem@users.noreply.github.com>

types/dnstype/dnstype_view.go

@@ -84,10 +84,35 @@ func (v *ResolverView) UnmarshalJSONFrom(dec *jsontext.Decoder) error {
 	return nil
 }
 
+// Addr is the address of the DNS resolver, one of:
+//   - A plain IP address for a "classic" UDP+TCP DNS resolver.
+//     This is the common format as sent by the control plane.
+//   - An IP:port, for tests.
+//   - "https://resolver.com/path" for DNS over HTTPS; currently
+//     as of 2022-09-08 only used for certain well-known resolvers
+//     (see the publicdns package) for which the IP addresses to dial DoH are
+//     known ahead of time, so bootstrap DNS resolution is not required.
+//   - "http://node-address:port/path" for DNS over HTTP over WireGuard. This
+//     is implemented in the PeerAPI for exit nodes and app connectors.
+//   - [TODO] "tls://resolver.com" for DNS over TCP+TLS
 func (v ResolverView) Addr() string { return v.ж.Addr }
+
+// BootstrapResolution is an optional suggested resolution for the
+// DoT/DoH resolver, if the resolver URL does not reference an IP
+// address directly.
+// BootstrapResolution may be empty, in which case clients should
+// look up the DoT/DoH server using their local "classic" DNS
+// resolver.
+//
+// As of 2022-09-08, BootstrapResolution is not yet used.
 func (v ResolverView) BootstrapResolution() views.Slice[netip.Addr] {
 	return views.SliceOf(v.ж.BootstrapResolution)
 }
+
+// UseWithExitNode designates that this resolver should continue to be used when an
+// exit node is in use. Normally, DNS resolution is delegated to the exit node but
+// there are situations where it is preferable to still use a Split DNS server and/or
+// global DNS server instead of the exit node.
 func (v ResolverView) UseWithExitNode() bool      { return v.ж.UseWithExitNode }
 func (v ResolverView) Equal(v2 ResolverView) bool { return v.ж.Equal(v2.ж) }