[Frontend]: Connect optional variables frontend to a backend part

Why are we doing this work

As customers work to strike a balance between security/compliance and developer velocity, enforcement of CI jobs within project pipelines is only one dimension. There is also a desire to control the behavior for managing and manipulating variables for jobs in a project enforced by a pipeline execution policy.

frontend part will be ready before backend and will be behind feature flag

Once backend is ready, we need to make sure everything works together

Relevant links

Non-functional requirements

• Documentation:
• Feature flag: optional_variables_control
• Performance:
• Testing:

Implementation plan

Verification steps