CI pipeline improvements (more label control)

A few tweaks in anticipation to the policy changes:

https://infra.apache.org/github-actions-policy.html

 - refactored the env vars into 'outputs' of the base-build job since
   env vars can't be used everywhere but outputs can
 - more jobs are off by default and can be activated with labels
   (enterprise, javafx, profiler, versioning...)
 - matrix got further reduced for runs outside of PRs