Feature Request: API endpoint for analytics.html

[g-saracca]

Overview of the Feature Request
For the SPA, we need an API endpoint that returns, if set, the installation analytics.html.
See Dataverse Guides docs about it.
We will modified the existing JSF related only analytics.html to work also for the SPA.
Notes:

• The Content-Type should be text/html; charset=utf-8 if I'm not wrong.
• @qqmyers mentioned this and this existing code.
• I suppose a 404 should be returned if this file is not configured? not sure about that.

What kind of user is the feature intended for?
SPA Users, API Users.

What inspired the request?
SPA Q2 Roadmap

Any open or closed issues related to this feature request?
IQSS/dataverse-frontend#245