[Functionality] Verify that all template fields are editable and that changes are saved correctly

[KurtiakRostyslav]

Priority: Critical

Preconditions

1. Administrator user is logged in;
2. Templates section is displayed with template cards;
3. Test templates have existing data.

Steps to reproduce

1. Click on the template card to enter edit mode;
2. Click on the Title field;
3. Change the title text (enter a new title up to 60 characters);
4. Click on the "Description" field;
5. Change the description text (enter a new description up to 600 characters);
6. Click on the "Image" field;
7. Replace the current image with a new image file;
8. Save the changes (find and click the "Save" button);
9. Verify the changes by refreshing the page/backing off and back on.

Expected result

The title field accepts text for input and allows editing
The description field accepts text for input and allows editing
The image field allows replacing the image file
All changes saved successfully
Changes are saved after page refresh
Character limits apply during editing

Postconditions
All template fields edited successfully
Changes are saved in the system
No data loss

User story:
#646

Related bug: