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/shared/Stubs/ProjectInformationParserStub.ts

@@ -4,7 +4,7 @@ import { IProjectInformation } from '@/domain/IProjectInformation';
 import { ProjectInformationStub } from './ProjectInformationStub';
 
 export class ProjectInformationParserStub {
-  public readonly arguments = new Array<IAppMetadata>();
+  public readonly arguments = new Array<IAppMetadata | undefined>();
 
   private returnValue: IProjectInformation = new ProjectInformationStub();