add query to support broader domain visibility in franklin dashboard for internal users

[langswei]

Is your feature request related to a problem? Please describe.
The project at franklin-dashboard (to be data.hlx.live) was initially built for single-domain usage for customers. Separately, it is common for internal people to request aggregated data across multiple domains. There would be some leverage from combining internal use cases in the same dashboard.

Describe the solution you'd like
A query which takes domainkey as an input and returns true or false. True means the domainkey (and therefore user) can see all domains, and false means either the domainkey is not valid or the domainkey can only see a single domain. The query would be called by the dashboard, and if the result is true then some additional menu options would appear.

Describe alternatives you've considered
The internal dashboard could be a separate, authenticated Franklin site but even in that case it would still require some sort of domainkey authentication which belongs in this repo.

Additional context
There has been some discussion of domain groups which would allow for a domainkey to match more than one domain but less than all domains. In that case, some of the implementation details of this feature may need to change -- to be determined.

[langswei]

https://github.com/adobe/helix-run-query/blob/domainkey-all/src/queries/dash/auth-all-domains.sql