[TC][Admin/Partners page] [Functionality] Admin is able to mark a partner as a "Ключовий партнер" via a checkbox

**Priority: Medium**

**Preconditions**
1. Go to the site - https://frontend.historycode.online/admin-panel.
2. Login as admin.
3. Go to the block "Admin/Партнери".

**Steps to reproduce**
1. Click on the red button "Створити партнера".
2. Click the checkbox "Ключовий партнер".
3. Add 5 symbols to the "Назва" field.
4. Add picture to the "Лого" field. Format files ("jpeg", "png", "webp"). The file size limit to 3 MB.
5. Click on the button "Зберегти"

**Expected result**
1. From the admin side, the name of the partner is displayed with the icon "Star".
2. This partner should be displayed as a key main partner from user site (bigger size of the logotype - 350x106 px).

**[User Story #1491](https://github.com/ita-social-projects/StreetCode/issues/1491)**

**Related bug:**