Migrate web_ide_extensions_marketplace ff to data

DEPENDS ON: Add db migration for vscode_extension_marketplace (!181038 - merged)

What does this MR do and why?

Migrate web_ide_extensions_marketplace ff to data

• If the feature flag is enabled globally then we'll assume that the instance wants to seemlessly transition to the feature being enabled within the application settings.

Changelog: changed

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After migrating with ff enabled

How to set up and validate locally

1. Enabled web_ide_extensions_marketplace and vscode_web_ide feature flags locally.
2. Run bundle exec rake db:migrate
3. Confirm that the application settings vscode_extension_marketplace is now {"enabled":true,"preset":"open_vsx"}
4. Run bundle exec rake db:migrate:down:main VERSION=20250228183319
5. Disable web_ide_extensions_marketplace locally.
6. Run bundle exec rake db:migrate:up:main VERSION=20250228183319
7. Confirm that the application settings vscode_extension_marketplace is now {}