1. Fix: "No data found" error check failed. Check error message instead of value.

1. Add: Lock for CRUD operations in pack bucket

1. Fix: "requiredData" not updated in index file

1. Fix: Failed update and upsert media operations due to row name conflict. Chnaged rowId from IndexNameQuery to relative filepath hash.

1. Addressed unhandled errors, variable assignments.
2. Commented dead code. Can be removed after stable release.

1. Add: Required data on get asset in header.
2. Fix: Update and delete operations for normal bucket.

update: updating lazywrite interval
modification:removing unnecessary files 

1. Fix: Failed to get asset fro Asset type FDB.

1. Fix: Required Error type not set in case of delete operation

1. Fix: Error while updating data which is not present

1. Fix: Asset not saved to mixed bucket due to extra index field "name".
2: Fix: Failed to get saved asset due to missing "rowID" in index.

1. FIx: Error not handled on index update

* added encryption support in fdb 
* added feature of dynamic encryption key generation function

added global lock for lazy write in append  bucket 

moved packfile related functions in filemdl and done changes in fdb accordingly