Add release/milestone workflows

- Add one full kick workflows for doing milestone or release.
- Use new central infra for all workflows
- Still keep old manual central workflows as we probably need
  those until branches are fixes to use new workflows for central.
- Separate artifactory build names so that we have unique ones
  for snapshot/milestone/release per branch as otherwise
  jfrog artifact download might be inaccurate.
- Use github environments to pause workflow for promotion and
  central sync to be able manually check that staged and released
  artifacts looks ok.
- Add tweaks to gradle build to ease switching to milestone, release
  or next dev version.

.github/workflows/central-sync-create.yml

@@ -43,17 +43,12 @@ jobs:
       id: nexus
       with:
         url: ${{ secrets.OSSRH_URL }}
-        username: ${{ secrets.OSSRH_USERNAME }}
-        password: ${{ secrets.OSSRH_PASSWORD }}
+        username: ${{ secrets.OSSRH_S01_TOKEN_USERNAME }}
+        password: ${{ secrets.OSSRH_S01_TOKEN_PASSWORD }}
         staging-profile-name: ${{ secrets.OSSRH_STAGING_PROFILE_NAME }}
         create: true
         upload: true
         generate-checksums: true
-        generate-checksums-config: >
-          [
-            { "type": "md5", "extension": "md5" },
-            { "type": "sha1", "extension": "sha1" }
-          ]
         pgp-sign: true
         pgp-sign-passphrase: ${{ secrets.GPG_PASSPHRASE }}
         pgp-sign-private-key: ${{ secrets.GPG_PRIVATE_KEY_WITH_HEADER }}