Update TypeScript config to ES2020 with bundler resolution and fix Ajv import

Changes module system from Node16 to ES2020 with bundler resolution, adds allowSyntheticDefaultImports flag, and updates Ajv import to use default import instead of named import.

Author: mattzcarey

src/validation/ajv-provider.ts

@@ -2,7 +2,7 @@
  * AJV-based JSON Schema validator provider
  */
 
-import { Ajv } from 'ajv';
+import Ajv from 'ajv';
 import _addFormats from 'ajv-formats';
 import type { JsonSchemaType, JsonSchemaValidator, JsonSchemaValidatorResult, jsonSchemaValidator } from './types.js';
 

tsconfig.json

@@ -1,14 +1,15 @@
 {
     "compilerOptions": {
-        "target": "es2018",
-        "module": "Node16",
-        "moduleResolution": "Node16",
+        "target": "es2020",
+        "module": "es2020",
+        "moduleResolution": "bundler",
         "declaration": true,
         "declarationMap": true,
         "sourceMap": true,
         "outDir": "./dist",
         "strict": true,
         "esModuleInterop": true,
+        "allowSyntheticDefaultImports": true,
         "forceConsistentCasingInFileNames": true,
         "resolveJsonModule": true,
         "isolatedModules": true,