Refactor to enforce strictNullChecks

This commit applies `strictNullChecks` to the entire codebase to improve
maintainability and type safety. Key changes include:

- Remove some explicit null-checks where unnecessary.
- Add necessary null-checks.
- Refactor static factory functions for a more functional approach.
- Improve some test names and contexts for better debugging.
- Add unit tests for any additional logic introduced.
- Refactor `createPositionFromRegexFullMatch` to its own function as the
  logic is reused.
- Prefer `find` prefix on functions that may return `undefined` and
  `get` prefix for those that always return a value.

tests/unit/presentation/components/Shared/Hooks/UseRuntimeEnvironment.spec.ts

@@ -1,21 +1,8 @@
 import { describe, it, expect } from 'vitest';
 import { useRuntimeEnvironment } from '@/presentation/components/Shared/Hooks/UseRuntimeEnvironment';
-import { itEachAbsentObjectValue } from '@tests/unit/shared/TestCases/AbsentTests';
 import { RuntimeEnvironmentStub } from '@tests/unit/shared/Stubs/RuntimeEnvironmentStub';
 
 describe('UseRuntimeEnvironment', () => {
-  describe('environment is absent', () => {
-    itEachAbsentObjectValue((absentValue) => {
-      // arrange
-      const expectedError = 'missing environment';
-      const environmentValue = absentValue;
-      // act
-      const act = () => useRuntimeEnvironment(environmentValue);
-      // assert
-      expect(act).to.throw(expectedError);
-    });
-  });
-
   it('returns expected environment', () => {
     // arrange
     const expectedEnvironment = new RuntimeEnvironmentStub();