[Story] Active recording downloads from S3

[andrewazores]

The API should expose an endpoint that allows clients to download the current contents of JFR files from target applications. In Cryostat 2.4 and prior this is available directly via /api/v1/targets/:targetId/recordings/:recordingName as well as via the JWT-auth'd flow (used for graphical clients). The JWT flow replaced the original method due to auth difficulties when dealing with graphical clients (web browsers) but is annoying for headless client access. In this case I am in favour of re-implementing neither of these endpoints directly, and instead providing only a single v3 endpoint that can service any kind of client.