DEV: Improve discovery components plugin-outlets compatibility with existing customizations

This commit changes some plugin outlets in `<Discovery::Layout>`, `<Discovery::Navigation>` and `Discovery::Topics` to improve compatibility with existing customization, simplifying the migration process to the new discovery routes.

In these components, the standard plugin outlets will receive by default at least the arguments: `category` and `tag`.

Furthermore, two new wrapping plugin outlets were added to enable the conversion of existing template overrides to the new pattern: `discovery-list-area` and `topic-list-bottom`. The new template overrides will receive a `model` argument containing the full model handled by the route.

---------

Co-authored-by: David Taylor <david@taylorhq.com>

app/assets/javascripts/discourse/app/components/discovery/layout.hbs

@@ -1,28 +1,37 @@
 <div class="container">
   <DiscourseBanner />
-  {{#if @category}}
+  {{#if @model.category}}
     <CategoryReadOnlyBanner
-      @category={{@category}}
+      @category={{@model.category}}
       @readOnly={{@createTopicDisabled}}
     />
   {{/if}}
 </div>
 
 <span>
-  <PluginOutlet @name="discovery-list-controls-above" @connectorTagName="div" />
+  <PluginOutlet
+    @name="discovery-list-controls-above"
+    @connectorTagName="div"
+    @outletArgs={{hash category=@model.category tag=@model.tag}}
+  />
 </span>
 
 <div class="list-controls">
   <PluginOutlet
     @name="discovery-navigation-bar-above"
     @connectorTagName="div"
+    @outletArgs={{hash category=@model.category tag=@model.tag}}
   />
   <div class="container">
     {{yield to="navigation"}}
   </div>
 </div>
 
-<PluginOutlet @name="discovery-above" @connectorTagName="div" />
+<PluginOutlet
+  @name="discovery-above"
+  @connectorTagName="div"
+  @outletArgs={{hash category=@model.category tag=@model.tag}}
+/>
 
 <div class="container list-container">
   <div class="row">
@@ -31,26 +40,43 @@
         {{yield to="header"}}
         <PluginOutlet
           @name="header-list-container-bottom"
-          @outletArgs={{hash category=@category}}
+          @outletArgs={{hash category=@model.category tag=@model.tag}}
         />
       </div>
     </div>
   </div>
   <div class="row">
     <div class="full-width">
-      <PluginOutlet @name="before-list-area" />
+      <PluginOutlet
+        @name="before-list-area"
+        @outletArgs={{hash category=@model.category tag=@model.tag}}
+      />
       <div id="list-area">
+        <PluginOutlet
+          @name="discovery-list-area"
+          @outletArgs={{hash
+            category=@model.category
+            tag=@model.tag
+            model=@model
+          }}
+          @defaultGlimmer={{true}}
+        >
           <PluginOutlet
             @name="discovery-list-container-top"
             @connectorTagName="span"
-          @outletArgs={{hash category=@category}}
+            @outletArgs={{hash category=@model.category tag=@model.tag}}
           />
           {{yield to="list"}}
+        </PluginOutlet>
       </div>
     </div>
   </div>
 </div>
 
 <span>
-  <PluginOutlet @name="discovery-below" @connectorTagName="div" />
+  <PluginOutlet
+    @name="discovery-below"
+    @connectorTagName="div"
+    @outletArgs={{hash category=@model.category tag=@model.tag}}
+  />
 </span>

app/assets/javascripts/discourse/app/components/discovery/navigation.hbs

@@ -3,7 +3,7 @@
 {{#if @category}}
   <PluginOutlet
     @name="above-category-heading"
-    @outletArgs={{hash category=@category}}
+    @outletArgs={{hash category=@category tag=@tag}}
   />
 
   <section class="category-heading">
@@ -18,7 +18,7 @@
       <PluginOutlet
         @name="category-heading"
         @connectorTagName="div"
-        @outletArgs={{hash category=@category}}
+        @outletArgs={{hash category=@category tag=@tag}}
       />
     </span>
   </section>

app/assets/javascripts/discourse/app/components/discovery/topics.hbs

@@ -114,6 +114,15 @@
 <footer class="topic-list-bottom">
   <ConditionalLoadingSpinner @condition={{@model.loadingMore}} />
   {{#if this.allLoaded}}
+    <PluginOutlet
+      @name="topic-list-bottom"
+      @outletArgs={{hash
+        category=@category
+        tag=@tag
+        allLoaded=this.allLoaded
+        model=@model
+      }}
+    >
       <TopicDismissButtons
         @position="bottom"
         @selectedTopics={{@bulkSelectHelper.selected}}
@@ -155,5 +164,6 @@
           }}
         {{/if}}
       </FooterMessage>
+    </PluginOutlet>
   {{/if}}
 </footer>

app/assets/javascripts/discourse/app/templates/discovery/categories.hbs

@@ -1,4 +1,4 @@
-<Discovery::Layout>
+<Discovery::Layout @model={{this.model}}>
   <:navigation>
     <Discovery::Navigation
       @showCategoryAdmin={{this.model.can_create_category}}

app/assets/javascripts/discourse/app/templates/discovery/filter.hbs

@@ -1,4 +1,4 @@
-<Discovery::Layout>
+<Discovery::Layout @model={{this.model}}>
   <:navigation>
     <Discovery::FilterNavigation
       @queryString={{this.q}}

app/assets/javascripts/discourse/app/templates/discovery/list.hbs

@@ -1,5 +1,5 @@
 <Discovery::Layout
-  @category={{this.model.category}}
+  @model={{this.model}}
   @createTopicDisabled={{this.createTopicDisabled}}
 >
   <:navigation>