feat(core, tests): add standalone getStatistics function and improve storage configuration

- **Core**: Introduced a new `getStatistics` utility function in `statistics.ts` for fetching database statistics at the root level of the library. Enhanced `BrainyData` methods to ensure metadata includes `id` field and refined statistics calculations, excluding verbs from the noun count.
- **Tests**: Added comprehensive test coverage in `statistics.test.ts` for the new utility function, validating proper error handling, statistics accuracy, and consistent results between instance methods and standalone function.
- **Storage Config**: Enabled dynamic support for AWS S3, Cloudflare R2, and Google Cloud Storage in web service configuration, utilizing environment variables for adapter setup. Addressed a race condition in `FileSystemStorage` initialization by deferring path module imports.

**Purpose**: Enhance database analytics by introducing a reusable `getStatistics` function, improve flexibility in storage configuration, and ensure robust testing for reliability and accuracy.

src/index.ts

@@ -23,14 +23,16 @@ import {
     euclideanDistance,
     cosineDistance,
     manhattanDistance,
-    dotProductDistance
+    dotProductDistance,
+    getStatistics
 } from './utils/index.js'
 
 export {
     euclideanDistance,
     cosineDistance,
     manhattanDistance,
-    dotProductDistance
+    dotProductDistance,
+    getStatistics
 }
 
 // Export embedding functionality