enhancement: global search-function for artifacts

[afischer211]

I want to search for artifacts in different channels based on artifactId or type or filename.
A global search function with a simple Web-GUI would be a good solution.

[ctron]

There is already a wiki page about a possible query language: https://github.com/ctron/package-drone/wiki/Proposal-for-Query-Language

[afischer211]

That is right (I have already extended this wiki page with some words). But we need also a Web-GUI (or a REST-API) for sending a query-request.