feat: Add Enterprise App Protection extension with settings and popup UI

- Implement manifest.json for Chrome extension with necessary permissions and background scripts.
- Create options.html for user settings including Google Safe Browsing API key, domains database URL, update interval, and warning message template.
- Develop options.js to handle loading and saving settings using Chrome storage.
- Design popup.html to display suspicious links and provide options to update the database and manage domains.
- Implement popup.js to manage interactions in the popup, including updating the database and resetting the suspicious links counter.
- Add testsite.html for dynamic testing of the extension with both official and fake links.

config.js

@@ -0,0 +1,9 @@
+// config.js
+const CONFIG = {
+  // URL to fetch the approved enterprise domains list
+  DOMAINS_DB_URL: 'https://raw.githubusercontent.com/rrpbergsma/EnterpriseAppProtection/refs/heads/main/domains.json',
+  // Update interval in hours
+  UPDATE_INTERVAL: 24,
+  // Warning message template for suspicious links
+  WARNING_TEMPLATE: "Warning: This link claims to be {app} but goes to an unofficial domain."
+};