Add support for Gradle

[m-reza-rahman]

Add support for generating Gradle projects, at least in the Starter UI if not also via command line (possibly via a custom CLI). Gradle support for IDEs could also be pursued via custom plugins.

[m-reza-rahman]

The current consensus is that this is a low priority item to be implemented after the more important priorities are addressed. Concise input from key community members can be found here: https://docs.google.com/spreadsheets/d/1bthiYVjX_UK7Xp2qQmq93awPwVhVCDnprGdzeMtv_ow/edit?usp=sharing. A discussion thread on the mailing list can be found here: https://www.eclipse.org/lists/starter-dev/msg00187.html.

[m-reza-rahman]

Personally I agree this is a low priority feature. Maven is pretty standard for Jakarta EE projects that I have seen. To start with, this could simply be instructions on how to convert from Maven to Gradle.

I do however think it is a bad idea to ignore this requirement for too long. This was one of the feedback items from the 1.0 release, along with the need for a Starter UI in addition to Archetypes. This is why this issue was initially created. All the other Starters including the Spring and MicroProfile ones have support for Gradle, so it would be odd for us to not prioritize this at all. Most reports (e.g. https://snyk.io/jvm-ecosystem-report-2021/) show approximately a third of developers using Gradle. This is not a population we can afford to outright ignore for too long.

[kito99]

I agree with @m-reza-rahman -- lots of folks use Gradle, so once we get the key features working with Maven, we should move on to Gradle sooner rather than later. We should also build things such that it's easy to add Gradle support later.