[Chore] Extract BuildInfo utility from Cryostat and Agent

[andrewazores]

https://github.com/cryostatio/cryostat-agent/blob/948ed9893243d487de4c42c74dae995d3e2d478d/src/main/java/io/cryostat/agent/BuildInfo.java#L27

https://github.com/cryostatio/cryostat/blob/96fbfc1bc2ee3aa115e78e207d32d712e9e7059d/src/main/java/io/cryostat/BuildInfo.java#L29

cryostatio/cryostat-agent#508 (review)