[TC][Admin/Partners] Verify that admin can add new partner via "Додати" button in the "Партнери" block

**Priority:** High

**Preconditions**
1. Go to the site.
2. Login as admin.
3. Open the new StreetCode page or the StreetCode page for editing.

**Steps to reproduce**
1. Scroll down to the "Партнери" block.
2. Click on the "Додати" button.
3. Fill mandatory fields ("Назва", "Лого") in the modal window.
4. Click on the "Зберегти" button.

**Expected result**
Added partner is displayed in dropdown in the input field in the "Партнери" block and saved on the "Партнери" page.

**User story:** #499