UX: unify ai representing icon (#257)

This PR addresses the effort to use one icon representing discourse-ai.

Removed discourse-sparkles from discourse-ai, now included in core ``vendor/assets/svg-icons/discourse-additional.svg``

assets/javascripts/discourse/connectors/topic-more-content/related-topics.js

@@ -30,7 +30,7 @@ export default class extends Component {
     this.moreTopicsPreferenceTracking.registerTopicList({
       name: I18n.t("discourse_ai.related_topics.pill"),
       id: this.listId,
-      icon: "magic",
+      icon: "discourse-sparkles",
     });
   }
 

lib/modules/ai_helper/entry_point.rb

@@ -13,7 +13,7 @@ module DiscourseAi
           Rails.root.join("plugins", "discourse-ai", "db", "fixtures", "ai_helper"),
         )
 
-        additional_icons = %w[discourse-sparkles spell-check language]
+        additional_icons = %w[spell-check language]
         additional_icons.each { |icon| plugin.register_svg_icon(icon) }
       end
     end

svg-icons/plugin-icons.svg

@@ -1,10 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<svg xmlns="http://www.w3.org/2000/svg" style="display: none;">
-  <!-- "Discourse Sparkles" -->
-  <symbol id="discourse-sparkles" viewBox="0 0 563 541">
-    <path d="M352.5 0C352.5 0 358.001 40.4652 373.702 57.2979C390.639 75.4553 431 78.5 431 78.5C431 78.5 390.639 81.5447 373.702 99.7021C358.001 116.535 352.5 157 352.5 157C352.5 157 346.999 116.535 331.298 99.7021C314.361 81.5447 274 78.5 274 78.5C274 78.5 314.361 75.4553 331.298 57.2979C346.999 40.4652 352.5 0 352.5 0Z"/>
-    <path d="M475 61C475 61 481.166 110.486 498.768 131.071C517.755 153.277 563 157 563 157C563 157 517.755 160.723 498.768 182.929C481.166 203.514 475 253 475 253C475 253 468.834 203.514 451.232 182.929C432.245 160.723 387 157 387 157C387 157 432.245 153.277 451.232 131.071C468.834 110.486 475 61 475 61Z"/>
-    <path d="M237.5 0C237.5 0 254.142 139.438 301.647 197.44C352.89 260.009 475 270.5 475 270.5C475 270.5 352.89 280.991 301.647 343.56C254.142 401.562 237.5 541 237.5 541C237.5 541 220.858 401.562 173.353 343.56C122.11 280.991 0 270.5 0 270.5C0 270.5 122.11 260.009 173.353 197.44C220.858 139.438 237.5 0 237.5 0Z"/>
-  </symbol>
-</svg>
-