No clear message that uploading child image is mandatory (may want to make it not mandatory)

[ckelwin]

Describe the bug
It appears to be mandatory to upload a child image (as cannot save child record without uploading one), but there is no warning/error message.

To Reproduce
Steps to reproduce the behavior:

1. Login as parent.
2. Click on the (+) button at the bottom right to add a child.
3. In the Add child page:

• Child name = A
• Email = A
• Press save, without upload an image by clicking the add picture button.

4. Notice that nothing happens. No warning/message to indicate it's mandatory to add a picture.

Expected behavior
Either:

1. Have a message to indicate it's mandatory to upload an image, or
2. Make it not mandatory. And on the parent Dashboard, the child's image will be replaced with a 'default image'.

[ckelwin]

Opened a PR and ready for review. Got the branch prefix wrong though but it's in my forked repo, so hope it's not a problem?