Add proper YARD annotations for all methods

MR: Pending

Description

Based on the comment here, we would like to review and add proper YARD annotations for most of methods we have with workspace backend.

Also pls add a new CI pipeline for checking if there is any missing YARD to enforce it.

Acceptance Criteria

• review and add proper YARD annotations for most of methods we have with workspace backend
• add a new CI pipeline for checking if there is any missing YARD to enforce it