[PB-5714] Encrypt email attachements separately

[TamaraFinogina]

Description

Encrypt email text and attachements separately to preserve the structure

Related Issues

Relates to PB-5714

Checklist

• Changes have been tested locally.
• Unit tests have been written or updated as necessary.
• The code adheres to the repository's coding standards.
• Relevant documentation has been added or updated.
• No new warnings or errors have been introduced.
• SonarCloud issues have been reviewed and addressed.
• QA Passed

Testing Process

unit tests

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
97.2% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud