Refactor DI for simplicity and type safety

This commit improves the dependency injection mechanism by introducing a
custom `injectKey` function.

Key improvements are:

- Enforced type consistency during dependency registration and
  instantiation.
- Simplified injection process, abstracting away the complexity with a
  uniform API, regardless of the dependency's lifetime.
- Eliminated the possibility of `undefined` returns during dependency
  injection, promoting fail-fast behavior.
- Removed the necessity for type casting to `symbol` for injection keys
  in unit tests by using existing types.
- Consalidated imports, combining keys and injection functions in one
  `import` statement.

src/presentation/components/TheFooter/DownloadUrlListItem.vue

@@ -12,9 +12,8 @@
 <script lang="ts">
 import {
   defineComponent, PropType, computed,
-  inject,
 } from 'vue';
-import { InjectionKeys } from '@/presentation/injectionSymbols';
+import { injectKey } from '@/presentation/injectionSymbols';
 import { OperatingSystem } from '@/domain/OperatingSystem';
 
 export default defineComponent({
@@ -25,8 +24,8 @@ export default defineComponent({
     },
   },
   setup(props) {
-    const { info } = inject(InjectionKeys.useApplication);
-    const { os: currentOs } = inject(InjectionKeys.useRuntimeEnvironment);
+    const { info } = injectKey((keys) => keys.useApplication);
+    const { os: currentOs } = injectKey((keys) => keys.useRuntimeEnvironment);
 
     const isCurrentOs = computed<boolean>(() => {
       return currentOs === props.operatingSystem;