1.0.0 Release Candidate 1 of the SPDX Java Core library

What's Changed

• Document copy manager memory issue by @goneall in #5
• Code clean-up - fix IDE warnings by @goneall in #6
• Add CodeQL to workflows by @goneall in #7

Full Changelog: v0.1.0-Alpha...v1.0.0-RC1

Initial release of the SPDX Java Core Library

This is an Alpha release of the core library. It should be stable for development and evaluation.