DEV: Use category ids in more URLs preferentially

This is a followup to 374534f0

app/assets/javascripts/discourse/controllers/edit-category.js.es6

@@ -107,7 +107,7 @@ export default Controller.extend(ModalFunctionality, {
             slug: result.category.slug,
             id: result.category.id
           });
-          DiscourseURL.redirectTo("/c/" + Category.slugFor(model));
+          DiscourseURL.redirectTo(`/c/${Category.slugFor(model)}/${model.id}`);
         })
         .catch(error => {
           this.flash(extractError(error), "error");

app/assets/javascripts/discourse/helpers/category-link.js.es6

@@ -79,7 +79,7 @@ function defaultCategoryLinkRenderer(category, opts) {
   let restricted = get(category, "read_restricted");
   let url = opts.url
     ? opts.url
-    : Discourse.getURL("/c/") + Category.slugFor(category);
+    : Discourse.getURL(`/c/${Category.slugFor(category)}/${category.id}`);
   let href = opts.link === false ? "" : url;
   let tagName = opts.link === false || opts.link === "false" ? "span" : "a";
   let extraClasses = opts.extraClasses ? " " + opts.extraClasses : "";

app/assets/javascripts/discourse/models/category.js.es6

@@ -67,7 +67,7 @@ const Category = RestModel.extend({
 
   @discourseComputed("name")
   url() {
-    return Discourse.getURL("/c/") + Category.slugFor(this);
+    return Discourse.getURL(`/c/${Category.slugFor(this)}/${this.id}`);
   },
 
   @discourseComputed

test/javascripts/acceptance/category-edit-test.js.es6

@@ -36,7 +36,7 @@ QUnit.test("Editing the category", async assert => {
   assert.ok(!visible(".d-modal"), "it closes the modal");
   assert.equal(
     DiscourseURL.redirectedTo,
-    "/c/bug",
+    "/c/bug/1",
     "it does one of the rare full page redirects"
   );
 });

test/javascripts/helpers/create-pretender.js.es6

@@ -265,6 +265,7 @@ export default function() {
 
     this.put("/categories/:category_id", request => {
       const category = parsePostData(request.requestBody);
+      category.id = parseInt(request.params.category_id, 10);
 
       if (category.email_in === "duplicate@example.com") {
         return response(422, { errors: ["duplicate email"] });