Move WebIde namespace out of Gitlab namespace for lib

What does this MR do and why?

This MR does some cleanup/housekeeping for the Web IDE domain layer (i.e. files under lib and ee/lib)

Moves WebIde namespace out of Gitlab namespace (only for files under lib and ee/lib)

• It should be in its own top-level bounded context, not the Gitlab namespace which implies the 'platform' bounded context
• Also fix/remove rubocop TODO entries for lib and ee/lib

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Legacy IDE still functional

New IDE still functional

How to set up and validate locally

• Exploratory test all functionality related to new and legacy Web IDEs