fix(cursor, doc): Add explicit return types and casts to SmartdataDbCursor methods and update getCursorExtended signature in SmartDataDbDoc.

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartdata',
-  version: '5.8.0',
+  version: '5.8.1',
   description: 'An advanced library for NoSQL data organization and manipulation using TypeScript with support for MongoDB, data validation, collections, and custom data types.'
 }