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/checks/desktop-runtime-errors/check-desktop-runtime-errors/app/system-capture/window-title-capture.ts

@@ -1,6 +1,7 @@
 import { runCommand } from '../../utils/run-command';
 import { log, LogLevel } from '../../utils/log';
 import { SupportedPlatform, CURRENT_PLATFORM } from '../../utils/platform';
+import { filterEmpty } from '../../utils/text';
 
 export async function captureWindowTitles(processId: number) {
   if (!processId) { throw new Error('Missing process ID.'); }
@@ -67,7 +68,7 @@ async function captureTitlesOnLinux(processId: number): Promise<string[]> {
     return titleOutput.trim();
   }));
 
-  return titles.filter(Boolean);
+  return filterEmpty(titles);
 }
 
 let hasAssistiveAccessOnMac = true;