Populate env vars for build info

[sjohnr]

The following env vars can be populated.

• ARTIFACTORY_PROJECT_KEY
• ARTIFACTORY_BUILD_NAME (e.g. spring-security-6.2.x, currently defaults to project name)
• ARTIFACTORY_BUILD_NUMBER
• ARTIFACTORY_BUILD_URL
• ARTIFACTORY_BUILD_AGENT_NAME (optional, currently defaults to Gradle)
• ARTIFACTORY_BUILD_AGENT_VERSION (optional, currently defaults to current Gradle version)
• ARTIFACTORY_USER_AGENT_NAME
• ARTIFACTORY_USER_AGENT_VERSION
• ARTIFACTORY_VCS_REVISION

Related gh-17