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/Modules/RuntimeSanityValidator.spec.ts

@@ -1,7 +1,7 @@
 import { describe, it, expect } from 'vitest';
 import { ISanityCheckOptions } from '@/infrastructure/RuntimeSanity/Common/ISanityCheckOptions';
 import { RuntimeSanityValidator } from '@/presentation/bootstrapping/Modules/RuntimeSanityValidator';
-import { expectDoesNotThrowAsync, expectThrowsAsync } from '@tests/unit/shared/Assertions/ExpectThrowsAsync';
+import { expectDoesNotThrowAsync, expectThrowsAsync } from '@tests/shared/Assertions/ExpectThrowsAsync';
 
 describe('RuntimeSanityValidator', () => {
   it('calls validator with correct options upon bootstrap', async () => {