Update PMDB.Create_Database_Backup.sql

[Imran-imtiaz48]

The script has been improved with several enhancements:
• Added error handling using TRY...CATCH to catch and display issues during execution.
• Improved string handling with NVARCHAR for better Unicode support and used sp_executesql for safer dynamic SQL execution.
• Removed hardcoded backup paths, adding flexibility to set the backup folder path based on the server.
• Enhanced readability by grouping related PRINT statements and removing unnecessary debug outputs.
• Improved protection against SQL injection by constructing SQL statements safely. Next Steps suggested:
• Standardize backup path by replacing hardcoded values with a configuration table or parameter.
• Add proper logging to record backup success or failure for auditing.
• Ensure the procedure runs with least privilege necessary for security.
You can view and discuss this issue further in this pull request:
#9