Add Current Navigation Application Customizer

- Created a new SPFx Application Customizer for current navigation.
- Implemented core functionality to fetch and render navigation items from a SharePoint term set.
- Added styles for the navigation component using SCSS.
- Included localization support for English and German languages.
- Developed unit tests for core navigation functionalities.
- Configured TypeScript and TSLint settings for the project.
- Added validation scripts for static assets and package configuration.

tests/tsconfig.json

@@ -0,0 +1,12 @@
+{
+  "compilerOptions": {
+    "target": "es5", "module": "commonjs", "moduleResolution": "node",
+    "outDir": "../temp/tests", "rootDir": "..", "skipLibCheck": true,
+    "types": [], "lib": ["es5", "dom", "es2015.collection"]
+  },
+  "files": [
+    "../src/services/CurrentNavigationTypes.ts",
+    "../src/services/CurrentNavigationCore.ts",
+    "CurrentNavigationCore.test.ts"
+  ]
+}