Implement new UI component for icons #230

- Introduce `AppIcon.vue`, offering improved performance over the
  previous `fort-awesome` dependency. This implementation reduces bundle
  size by 67.31KB (tested for web using `npm run build -- --mode prod`).
- Migrate Font Awesome 5 icons to Font Awesome 6.

This commit facilitates migration to Vue 3.0 (#230) and ensures no Vue
component remains tightly bound to a specific Vue version, enhancing
code portability.

Font Awesome license is not included because Font Awesome revokes its
right:

> "Attribution is no longer required as of Font Awesome 3.0"
>
> Sources:
>
> - https://fontawesome.com/v4/license/ (archived: https://web.archive.org/web/20231003213441/https://fontawesome.com/v4/license/, https://archive.ph/Yy9j5)
> - https://github.com/FortAwesome/Font-Awesome/wiki (archived: https://web.archive.org/web/20231003214646/https://github.com/FortAwesome/Font-Awesome/wiki, https://archive.ph/C6sXv)

This commit removes following third-party production dependencies:

- `@fortawesome/vue-fontawesome`
- `@fortawesome/free-solid-svg-icons`
- `@fortawesome/free-regular-svg-icons`
- `@fortawesome/free-brands-svg-icons`
- `@fortawesome/fontawesome-svg-core`

src/presentation/components/Code/CodeButtons/IconButton.vue

@@ -4,30 +4,30 @@
     type="button"
     @click="onClicked"
   >
-    <font-awesome-icon
+    <AppIcon
       class="button__icon"
-      :icon="[iconPrefix, iconName]"
-      size="2x"
+      :icon="iconName"
     />
     <div class="button__text">{{text}}</div>
   </button>
 </template>
 
 <script lang="ts">
-import { defineComponent } from 'vue';
+import { defineComponent, PropType } from 'vue';
+import { IconName } from '@/presentation/components/Shared/Icon/IconName';
+import AppIcon from '@/presentation/components/Shared/Icon/AppIcon.vue';
 
 export default defineComponent({
+  components: {
+    AppIcon,
+  },
   props: {
     text: {
       type: String,
       required: true,
     },
-    iconPrefix: {
-      type: String,
-      required: true,
-    },
     iconName: {
-      type: String,
+      type: String as PropType<IconName>,
       required: true,
     },
   },
@@ -64,6 +64,10 @@ export default defineComponent({
   box-shadow: 0 3px 9px $color-primary-darkest;
   border-radius: 4px;
 
+  &__icon {
+    font-size: 2em;
+  }
+
   @include clickable;
 
   width: 10%;