Apply suggestions from code review

Co-authored-by: Owen Mansel-Chan <62447351+owen-mc@users.noreply.github.com>

go/ql/lib/semmle/go/frameworks/Twirp.qll

@@ -7,6 +7,7 @@ import semmle.go.security.RequestForgery
 module Twirp {
   /**
    * A *.pb.go file generated by Twirp.
+   *
    * This file contains all the types representing protobuf messages and should have a companion *.twirp.go file.
    */
   class ProtobufGeneratedFile extends File {
@@ -38,7 +39,7 @@ module Twirp {
   /**
    * A type representing a protobuf message.
    */
-  class ProtobufMessage extends Type {
+  class ProtobufMessageType extends Type {
     ProtobufMessage() {
       exists(TypeEntity te |
         te.getType() = this and
@@ -51,7 +52,7 @@ module Twirp {
    * An interface type representing a Twirp service.
    */
   class ServiceInterface extends InterfaceType {
-    NamedType serviceInterface;
+    NamedType namedType;
 
     ServiceInterface() {
       exists(TypeEntity te |
@@ -62,7 +63,7 @@ module Twirp {
     }
 
     /**
-     * Returns the name of the interface
+     * Gets the name of the interface.
      */
     override string getName() { result = serviceInterface.getName() }
 
@@ -73,7 +74,7 @@ module Twirp {
   }
 
   /**
-   * A Twirp client
+   * A Twirp client.
    */
   class ServiceClient extends NamedType {
     ServiceClient() {
@@ -104,8 +105,8 @@ module Twirp {
     ClientConstructor() {
       exists(ServiceClient c |
         this.getName().toLowerCase() = "new" + c.getName().toLowerCase() and
-        this.getParameter(0).getType().getName() = "string" and
-        this.getParameter(1).getType().getName() = "HTTPClient"
+        this.getParameter(0).getType() instanceof StringType and
+        this.getParameterType(1).getName() = "HTTPClient"
       )
     }
   }