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>

cmd/viewer/viewer_test.go

@@ -53,6 +53,7 @@ func TestViewerImports(t *testing.T) {
 			if err != nil {
 				t.Fatal(err)
 			}
+			var fieldComments map[fieldNameKey]string // don't need it for this test.
 
 			var output bytes.Buffer
 			tracker := codegen.NewImportTracker(pkg)
@@ -65,7 +66,7 @@ func TestViewerImports(t *testing.T) {
 				if !ok {
 					t.Fatalf("%q is not a named type", tt.typeNames[i])
 				}
-				genView(&output, tracker, namedType, pkg)
+				genView(&output, tracker, namedType, fieldComments)
 			}
 
 			for _, pkg := range tt.wantImports {