Export Donors tool should filter by donation date when a form isn't selected

[LMNTL]

User Story

As an admin, I want to export all donors within a date range so that I can see who made donations during that period.

Details

Currently, if 'All Forms' is selected when exporting, the date selector in the Donor Export tool applies to the donor creation date, not the donation creation date.

Expected Behavior

The date filter should always retrieve active donors who made donations within the given date range. It should not depend on whether a form is selected.

Steps to Reproduce

1. Install GiveWP
2. Create a new donation using a donor that registered before today.
3. In the admin area, go to Donations -> Tools
4. Scroll to Export Donors
5. Set today's date for the Start Date and End Date
6. Make sure 'All Forms' is selected
7. Click 'Generate CSV'
8. Verify that the donation created in Step 2 is not included in the CSV file, or if it was the only donation made today, that no CSV file is generated.

Acceptance Criteria

• [x] Export Donors tool should filter by donation date when a form isn't selected.
• [x] Exporting donors for all forms without a date set still works as usual.

[canny[bot]]

This issue has been linked to a Canny post: Export Donors tool date range should apply to donation creation date :tada:

[LMNTL]

Closed: duplicate of #6235.

[canny[bot]]

This issue has been unlinked from a Canny post: Export Donors tool date range should apply to donation creation date :cry: