Introduced tsconfig.app.json and tsconfig.base.json + Refactored eslint.config.js to the latest structure (#652)

* Introduced tsconfig.app.json and tsconfig.base.json

* yarn.lock

* Introduced tsconfig.app.json, tsconfig.base.jsonfig.

* Refactored eslint.config.js to latest structure

* Returned previous recommended rules.

* More rules

* Force import rules

* Check

* Check

* Cleanup ESLint configuration and plugins

* Cleanup heap: "writable",DD_RUM: "writable" from ESLint configuration

* "scripts" moved to the top of package.json

frontend/tsconfig.base.json

@@ -0,0 +1,32 @@
+{
+  "compilerOptions": {
+    /* Basic Options */
+    "target": "ESNext",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "lib": ["ESNext", "DOM", "DOM.Iterable"],
+    "useDefineForClassFields": true,
+    "jsx": "react-jsx",
+
+    /* Strictness */
+    "strict": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noFallthroughCasesInSwitch": true,
+    "noImplicitOverride": true,
+
+    /* Modern Module Handling */
+    "verbatimModuleSyntax": true,
+    "allowSyntheticDefaultImports": true,
+    "esModuleInterop": true,
+
+    /* Build & Performance */
+    "composite": true,
+    "incremental": true,
+    "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.tsbuildinfo",
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "resolveJsonModule": true,
+    "noEmit": true
+  }
+}