Fix validation for Bootstrap frameworks

[E-Fir]

Problem: initial validation messages don’t appear in some cases when any of Bootstrap frameworks are used.

How to reproduce:

• open the Demonstration Playground
• choose the "Bootstrap 3" or the "Bootstrap 4" framework
• choose the "Angular Scheme Form/Bootstrap Grid" example
• focus on the "Name" text input. Nothing is telling us that this field is required. Only if type something and remove all after that.
• focus out of the "Name" text input when no validation error message is shown. The validation error message doesn't appear.
• the same behavior with the "Email" field

Also, after I had wrote this I found a related issue: #315

Fix:

• force validation on update value in the json-schema-form service
• update value on focus in

[netlify]

✅ Deploy Preview for ajsf ready!

Name	Link
🔨 Latest commit	6d347d2
🔍 Latest deploy log	https://app.netlify.com/sites/ajsf/deploys/636a492a3487d100087b2ee4
😎 Deploy Preview	https://deploy-preview-332--ajsf.netlify.app/
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site settings.