[Admin page. Video] Input validation needs improvement.

**Environment:** all.
**Reproducible:** always.
**Build found:** last commit from https://github.com/ita-social-projects/GreenCityClient/tree/dev
E.g. "commit 147fa44"

**Preconditions**
Open `localhost:3000/admin-panel/new-streetcode`

**Steps to reproduce**
1. Scroll to the Video input block.
2. Enter invalid input, for example `facebook.com`

**Actual result**
No error message or anything to inform the user about the invalid input.

**Expected result**
Error message needs to be shown under the input field.

**Postconditions**
No specific post conditions.