Idea: Storage of Gateway name, description, URL and logo

Since the gateway is basically just a normal working group it appears there isn't a way for the gateway operator to signal basic identifying information to platform participants.

While there is an extrinsic called `workerRemark` and this could hypothetically be used in some socially agreed upon way with specific formatting to achieve this, I think it makes sense for gateways to be able to signal 4+ distinct pieces of information:
1. Name (Name of the gateway/app - although unclear if this should be something that is permanent)
2. Description (Description of what it does or what it focuses on, which could change over time)
3. Logo (URL to a logo file)
4. Tags (a series of tags the operator could add to define their gateway's purpose, such as `audio` or `viral videos`)
5. URL (simply the main web address to access the app, if relevant)
6. URL-2 (multiple URLs would have value if the same app runs on multiple platforms simultaneously. This could be a URL to go to the Android, Samsung TV, Apple app stores or even go to a Discord/chat server relevant to the gateway)
7. URL-3 (same as above)

If this is natively supported it would allow for apps and other platforms to be able to identify all active gateways/apps very easily without having to depend upon lists being generated by platform participants or relying upon social agreements regarding formatting.

It would basically allow for a "gateway explorer" to be developed, which could have huge value.

In particular by having items such as `logo` be distinct, this opens up further possibilities for external DAOs to run and manage their own gateways.