feat(checker): check process minor fixes & improvements (#518)

Description

This is a continuation of the work on !765 (merged).

• Fix jq cmd call in run_ci_checker.sh
• Add platform client configuration check method. This fixes the problem when the observer to freeze on startup via the /observation/start API endpoint (see also engine/internal/srv/routes.go:287) if platform client is configured with empty URL.
• Add new parameters CloneName to the StartMigrationRequest struct
• Always run /bin/sh on creating the migrations container.

Related issue

#518

Examples

Checklist

• MR description has been reviewed
• MR changes are functionally tested
• MR does NOT have API/CLI changes OR there are API/CLI changes and they have been reviewed & DOCS ARE ADJUSTED (reference doc, etc)
• MR does NOT have UI changes OR there are UI changes and they have been reviewed & UX IS REVIEWED

Closes #518