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/Instructions/CodeInstruction.vue

@@ -3,9 +3,9 @@
     <span class="dollar">$</span>
     <code><slot /></code>
     <TooltipWrapper>
-      <font-awesome-icon
+      <AppIcon
         class="copy-button"
-        :icon="['fas', 'copy']"
+        icon="copy"
         @click="copyCode"
       />
       <template v-slot:tooltip>
@@ -19,10 +19,12 @@
 import { defineComponent, useSlots } from 'vue';
 import { Clipboard } from '@/infrastructure/Clipboard';
 import TooltipWrapper from '@/presentation/components/Shared/TooltipWrapper.vue';
+import AppIcon from '@/presentation/components/Shared/Icon/AppIcon.vue';
 
 export default defineComponent({
   components: {
     TooltipWrapper,
+    AppIcon,
   },
   setup() {
     const slots = useSlots();