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`

tests/unit/shared/Assertions/ExpectThrowsAsync.ts

@@ -4,12 +4,13 @@ export async function expectThrowsAsync(
   method: () => Promise<unknown>,
   errorMessage: string,
 ) {
-  let error: Error;
+  let error: Error | undefined;
   try {
     await method();
   } catch (err) {
     error = err;
   }
+  expect(error).toBeDefined();
   expect(error).to.be.an(Error.name);
   if (errorMessage) {
     expect(error.message).to.equal(errorMessage);

tests/unit/shared/Stubs/UseSvgLoaderStub.ts

@@ -0,0 +1,31 @@
+import {
+  WatchSource, computed, ref, watch,
+} from 'vue';
+import { IconName } from '@/presentation/components/Shared/Icon/IconName';
+import { useSvgLoader } from '@/presentation/components/Shared/Icon/UseSvgLoader';
+
+export class UseSvgLoaderStub {
+  private readonly icons = new Map<IconName, string>();
+
+  public withSvgIcon(name: IconName, svgContent: string): this {
+    this.icons.set(name, svgContent);
+    return this;
+  }
+
+  public get(): typeof useSvgLoader {
+    return (iconWatcher: WatchSource<IconName>) => {
+      const iconName = ref<IconName | undefined>();
+      watch(iconWatcher, (newIconName) => {
+        iconName.value = newIconName;
+      }, { immediate: true });
+      return {
+        svgContent: computed<string>(() => {
+          if (!iconName.value) {
+            return '';
+          }
+          return this.icons.get(iconName.value) || '';
+        }),
+      };
+    };
+  }
+}