CLI: Worker application form displays answers incorrectly

## Context

When creating application via CLI some of the answers are skipped (as its in metaprotocol, cannot be made mandatory), which causes the form to be rendered incorrectly when some answers are skipped.

Here's the chat with @RadoslawWyszynski

⚠️ Related CLI issue: https://github.com/Joystream/joystream/issues/4149

## Scope
- [ ] Fix the handling of submitting the empty strings

## More info

As far a I know, when creating an application, there is no way to mark certain questions as mandatory. Due to this design, applicant often skip questions they feel uncomfortable to answer or simply not knowing what to answer :)

This is completely fine, we are all people after all! However, if an application form has some skipped questions, it is displayed incorrectly in Pioneer UI.

Example:

In this example, an applicant chose not to answer the question about compensation model. Because of this, his next answer (asking for Github link) is shown **shifted** one row up. This makes the form very hard-to-read and needs to be fixed.