Paper filing error messaging

[swongCO]

As an internal DAWSON user, so that I know what errors to correct, I need error messaging to be accurate.

Description

There are two different error messages in the Add paper filing flow for the Add document component.

1. Log in as a docket clerk
2. Go to a case and click Add Paper Filing
3. Fill in fields except for a required one and don't scan or upload a document
4. Click Save and Serve
5. Notice the error messages
6. Correct the required field and click Save and Serve
7. Notice the error message changed for the Add Document component

This was part of feedback for 10074 but was separated out. @Mwindo is able to provide more context as to the fix.

Acceptance Criteria

• Replace "Upload a document" with the more descriptive "Scan or upload a document to serve, or click Save for Later to serve at a later time"
• Determine if user documentation needs to be updated (Tenille): Y / N