feat : download document with watermark

**Is your feature request related to a problem? Please describe.**
For Document Management , it is critical for the organisation to allow the download but with an option of watermark in the background (e.g. Draft, Confidential , company name , logo etc)

**Describe the solution you'd like**

Drive Setting Fields :
Allow Documents to Download with Watermark ( checkbox) ,
System level Watermark Type :Text / Image ( Select / Options)
If Image : Watermark Image (Attach Image)
If Text : Watermark Text : (Data)

**Describe alternatives you've considered**
Alternatives are difficult , but would require to upload an already watermarked document.

Start with issue #449 and clarify the watermark requirements before locating an implementation entry point. Define what settings are needed for text and image watermarks, how they affect document downloads, and what scenarios must be tested before the feature is considered complete.

Written by the indexing model from the issue text.