Add Portal Settings Web Part with styles, localization, and tests

- Implemented the PortalSettings Web Part with a new manifest and TypeScript file.
- Created SCSS styles for the Web Part, defining various UI elements and responsive design.
- Added localization support for English and German languages.
- Developed tests for Provider Registry and static assets validation.
- Included PowerShell script for project validation.

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "portal-settings",
-  "version": "2.2.0",
+  "version": "3.0.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {