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/presentation/electron/main/index.ts

@@ -112,9 +112,9 @@ if (isDevelopment) {
 
 function loadApplication(window: BrowserWindow) {
   if (RENDERER_URL) { // Populated in a dev server during development
-    loadUrlWithNodeWorkaround(win, RENDERER_URL);
+    loadUrlWithNodeWorkaround(window, RENDERER_URL);
   } else {
-    loadUrlWithNodeWorkaround(win, RENDERER_HTML_PATH);
+    loadUrlWithNodeWorkaround(window, RENDERER_HTML_PATH);
   }
   if (isDevelopment) {
     window.webContents.openDevTools();