Check marketplace_home_url with user opt in

Issue: Update Extensions Marketplace user preferences ... (#508992 - closed)

Next MR: Enable extension marketplace by default (!184662 - merged)

What does this MR do and why?

Check marketplace_home_url with user opt in

• If a user has opted-in to marketplace A, we DO NOT want this to transfer over to marketplace B.
• For now, we store alongside the opt_in field, a url field, and check this field to determine the enablement.
• To avoid user_preference model from being too bloated, we move some business logic to its own class WebIde::ExtensionMarketplaceOptIn.

Screenshots or screen recordings

check_marketplace_home_url_demo

How to set up and validate locally

Prerequisites:

1. Enable feature flag web_ide_extensions_marketplace
2. Enable feature flag vscode_extension_marketplace_settings

NOTE: GitLab caches application settings and feature flags a bit. You might need to refresh the page a couple of times (and wait) for cache to catch up to changes.

Test user preferences after changing URL:

1. Go to Admin > Settings > General.
2. In the VS Code Extension Marketplace section, enable the extension marketplace, then toggle ON Use Open VSX and click Save changes.
3. Go to your user's profile preferences /-/profile/preferences.
4. In the Integrations section, look for Web IDE and Workspaces with checkbox Enable extension marketplace.
5. EXPECTATION: The url in this section should be https://open-vsx.org.
6. Check the checkbox and click Save changes.
7. Go to Admin > Settings > General.
8. In the VS Code Extension Marketplace section, toggle OFF Use Open VSX and for Service URL enter https://openvsx.test:8883/vscode/gallery, for Item URL enter https://openvsx.test:8883/vscode/item, for Resource URL Template enter https://openvsx.test:8883/vscode/unpkg/{publisher}/{name}/{versionRaw}/{path}, then click Save changes.
9. Go to your user's profile preferences /-/profile/preferences.
10. EXPECTATION: The checkbox should be UNCHECKED and the url in this section should be https://openvsx.test:8883.

How to setup local Open VSX proxy for more testing

This isn't required to test out this MR, but for the brave:

1. Make sure nginx is installed.

2. Update /etc/hosts with openvsx.test 127.0.0.1

3. Create a directory and create a file openvsx-proxy.conf with content:

   events {
     worker_connections  1024;
   }
   
   http {
     server {
       listen openvsx.test:8883 ssl;
       server_name openvsx.test;
    
       ssl_certificate openvsx.test.pem;
       ssl_certificate_key openvsx.test-key.pem;
   
       location / {
         proxy_pass https://open-vsx.org/;
       }
     }
   }
   

4. Inside the directory, run mkcert openvsx.test.

5. Start an nginx server with something like nginx -c ./openvsx-proxy.conf

6. Try visiting https://nginx.test:8883 locally to confirm if the server is up and running.

7. Now you can use the following custom_values in your vscode_extension_marketplace settings on the GDK:

   {
     "enabled":true,
     "preset":"custom",
     "custom_values": {
       "service_url":"https://openvsx.test:8883/vscode/gallery",
       "item_url":"https://openvsx.test:8883/vscode/item",
       "resource_url_template":"https://openvsx.test:8883/vscode/unpkg/{publisher}/{name}/{version}/{path}"
     }
   }