Maven support

[kephale]

It would be awesome to use Maven to provide packages through the updater.

See also: scijava/scijava-grab#1

[ctrueden]

I took the liberty of editing your description from "There is some interest in using" to "It would be awesome to use" since it would be totally awesome. 👍

[ctrueden]

Migrated from the "Maven-based Updater" project:

Goals

• We want fiji/fiji release to line up with a Stable Fiji update site.
• We want fiji/fiji master to line up with the Testing Fiji update site.
• More generally: we want an Updater mode that is Maven component driven.

Current thinking is to drive this support using the db-xml-maven tool I wrote, so that existing Fiji installations can still be updated easily.

I'm closing the Maven-based Updater project in favor of a new Fiji Fit project that covers this issue, along with the update to Java 21.