Add extensions gallery support to Remote Dev settings

Issue: Update `RemoteDevelopment::Settings` to handle ... (#455159 - closed)

What does this MR do and why?

Add extensions gallery support to Remote Dev settings

• See Update `RemoteDevelopment::Settings` to handle ... (#455159 - closed) for details.

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

See #455159 (closed)

How to set up and validate locally

See #455159 (closed)