use tmp folder to generate 1095a pdfs instead of aws folder

[saipraveen18]

https://app.clickup.com/t/868hj9ch3

Converting the Polypress pods from a StatefulSet to Deployment-based pods introduced an issue where 1095-A notices were still being appended to the /aws folder.

To resolve this, instead of creating and appending files to the /aws directory, I am using the temporary (/tmp) directory to generate the documents and then cleaning them up afterward.

This pull request updates the way file paths are determined for 1095A document generation and storage, making the logic conditional based on whether the S3 upload feature is enabled. The changes centralize the folder path logic and improve maintainability by reducing duplication.

Path management improvements:

• Introduced a base_folder_path method that determines the base directory for storing 1095A documents, switching between a local folder and a temporary directory based on the :upload_paper_notices_to_s3 feature flag.
• Updated folder creation in create_folder to use the new base_folder_path method, ensuring consistency across the codebase.
• Modified the PDF generation and document combination methods to use base_folder_path for constructing file and folder paths, replacing hardcoded path logic. [1] [2]

[geetha-1z]

looks good to me

[saikumar9]

lgtm!