(Feature) Keep watermark settings after generating PDF

[AB527]

Description

This PR improves the watermark generation workflow by persisting watermark settings after PDF generation instead of resetting them automatically.

Previously, generating a PDF would clear all watermark configurations, requiring users to re-enter the same settings for every iteration. This change ensures that watermark options (text and image) are retained until the user explicitly resets them, making iterative watermark adjustments significantly less tedious.

A Reset button has been added to allow users to manually clear watermark settings when required. Watermark configurations are now stored in local storage and restored automatically after PDF generation.

Fixes #291

Type of change

• New feature (non-breaking change which adds functionality)

🧪 How Has This Been Tested?

The changes were tested manually by performing multiple PDF generations in sequence using the same watermark settings.

Checklist:

• Verified output manually
• Tested with relevant sample documents or data
• Wrote Vite Test Case (if applicable)

Expected Results:

• Watermark settings persist after generating a PDF
• Reset button clears all watermark settings
• PDF generation works correctly across multiple iterations

Actual Results:

• Watermark settings persist as expected after PDF generation
• Reset button successfully clears both text and image watermark configurations
• No regressions or errors observed during repeated generations

Checklist:

• I have signed the Contributor License Agreement (CLA) or my organization has signed the Corporate CLA
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

Note to maintainers:
This is my first pull request to this project. I have tried to follow the guidelines as closely as possible, but please let me know if there is anything I missed or if there are any areas for improvement in the code. I'm happy to make any necessary changes. Thank you for your review !

[github-actions]

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[AB527]

I have read the CLA Document and I hereby sign the CLA