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.

tests/unit/presentation/bootstrapping/DependencyProvider.spec.ts

@@ -18,8 +18,9 @@ describe('DependencyProvider', () => {
       useCurrentCode: createTransientTests(),
     };
     Object.entries(testCases).forEach(([key, runTests]) => {
-      describe(`Key: "${key}"`, () => {
-        runTests(InjectionKeys[key]);
+      const registeredKey = InjectionKeys[key].key;
+      describe(`Key: "${registeredKey.toString()}"`, () => {
+        runTests(registeredKey);
       });
     });
   });