feat: add verb and noun metadata handling in storage adapters

- Implement saveVerbMetadata and getVerbMetadata methods for managing verb metadata.
- Implement saveNounMetadata and getNounMetadata methods for managing noun metadata.
- Update storage adapters to use HNSWVerb instead of GraphVerb for improved performance.
- Deprecate methods that require loading metadata for edges, returning empty arrays instead.

src/storage/adapters/baseStorageAdapter.ts

@@ -41,6 +41,10 @@ export abstract class BaseStorageAdapter implements StorageAdapter {
 
   abstract getMetadata(id: string): Promise<any | null>
 
+  abstract saveVerbMetadata(id: string, metadata: any): Promise<void>
+
+  abstract getVerbMetadata(id: string): Promise<any | null>
+
   abstract clear(): Promise<void>
 
   abstract getStorageStatus(): Promise<{