JsonWizard: Replace CppClassWizard with a JsonWizard

Change-Id: I4e1aeea4ccd1087b5e804e9ba4c2aa8fde4f4fcb
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>
JsonWizard: Enable validators for lineedits on Fields pages

Make use of a validator when entering C++ class names.

Change-Id: Id7f9c8c2e1fe036397a337595cbe7aa7fd9589d5
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>