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.

src/infrastructure/Log/WindowInjectedLogger.ts

@@ -4,8 +4,8 @@ import { ILogger } from './ILogger';
 export class WindowInjectedLogger implements ILogger {
   private readonly logger: ILogger;
 
-  constructor(windowVariables: WindowVariables = window) {
-    if (!windowVariables) {
+  constructor(windowVariables: WindowVariables | undefined | null = window) {
+    if (!windowVariables) { // do not trust strict null checks for global objects
       throw new Error('missing window');
     }
     if (!windowVariables.log) {