Add release supporting functionalities

At least some projects in this polaris-tools repository are going to be released.
Releases likely happen independently for each project in polaris-tools.

For Gradle based projects, much of the functionality that's already in the main Polaris repository can be reused, but needs to be adopted. At best in a way that's common across all Gradle based project including the main Polaris repository.

The issue names no files, tests, or entry points. Start by comparing the existing release functionality in the main Polaris repository with the Gradle-based projects in polaris-tools; done means independently releasable projects share the adopted functionality where appropriate.

Written by the indexing model from the issue text.