use an embedded http server that is light and requires just Java 7

With site:run it is possible to view the static content as if it was hosted on a webserver. This issue is about looking for alternative implementation to do that. It should be as simple as: map the context path to a specific folder. Now you should be able to view it on a local port via a browser.

with Jetty upgrade for security reasons in MSITE-829 (even if security reasons could be discussed in "mvn site:run" scenario: we're not in a permanent webserver, just a developer temporary one that should be limited to localhost requests handling), Java 8 is required when our target currently is Java 7

this is perhaps the right moment to look for a light http server that would not require Java 8: there are many options available like https://syntaxcorrect.com/Java/5_Ultra_Lightweight_Http_Server_Implementations_in_Java_for_Blazing_Fast_Microservices_APIs_or_Even_Websites or any other idea