Generate Donations screen is now completed

[alaca]

Resolves #3

Description

This PR completes the Generate Donations screen. Admin is now able to generate donations from Admin UI by selecting a donation status, donations count, and donation revenue.

Affects

Generate Donations screen.

Visuals

Pre-review Checklist

• [x] Acceptance criteria satisfied and marked in related issue
• [x] Relevant @since tags included in DocBlocks
• [x] Changes logged to the Unreleased section of CHANGELOG.md
• [x] Self Review of code and UX completed

Testing Instructions

1. Go to Donations -> Tools -> TestData -> Generate Donations
2. Check the status of the donation which you want to generate, enter donation count and click on Generate btn