CR - allow examiner to upload documents to new, open applications on behalf of applicants

**Description:**
Examiners currently do not have the ability to upload documents to new, open applications on behalf of applicants.

**Current behavior:**

For applications which do not currently have a registration, there is no ability for an examiner to upload documents on the applicant's behalf. We would like to add this ability.

What is the expected behaviour?:
Examiners should be able to upload documents to open, new applications in the same manner they currently do on registrations.

When an application is approved, all documents, including ones uploaded by examiners, are added to
the new registration details page.

After an approval decision is made in an application (registration exists for the application), examiners should no longer be able to upload documents via the application page, only in the registration page moving forward.

**Who is affected?:**
Examiners

**How does the bug/issue affect your work as an examiner?:**
If a NOC is issued to an application and it expires, any document submissions have to be done by the applicant via email. The documents then have to be stored via Outlook or the LAN. If the application is approved, an examiner would have to search through Outlook/the LAN and upload documents to a registration page
Being able to upload documents to an open application will cut the extra time it takes to manage documents in Outlook/the LAN. There will be less opportunities for errors (ie. accidentally deleting an email w/ documents in Outlook)

## Acceptance Criteria
> Generated by [Zenhub AI](https://www.zenhub.com/ai)

### Acceptance Criteria

- [ ] **Scenario: Examiner uploads a document to a new or open application**
- Given an examiner is viewing an application that is in a "New" or "Open" status
- And no registration has been created for this application yet
- When the examiner selects and uploads a document on behalf of the applicant
- Then the document should be successfully saved to the application
- And the document should be visible in the application's document list

- [ ] **Scenario: Documents persist from application to registration after approval**
- Given an examiner has uploaded documents to an open application
- When the application is approved and a registration is created
- Then all documents uploaded during the application phase (including those uploaded by the examiner) must be visible on the registration details page

- [ ] **Scenario: Upload functionality is disabled on the application page after approval**
- Given an application has been approved and a registration record now exists
- When the examiner views the original application page
- Then the ability to upload documents should be hidden or disabled on that page

- [ ] **Scenario: Examiner uploads a document to an existing registration**
- Given an examiner is viewing a registration details page
- When the examiner uploads a document
- Then the document should be successfully saved to the registration (maintaining existing functionality)