[Bug] Operator Architecture information does not describe presigned file transfers

The Operator Config guide (#241 , port of https://github.com/cryostatio/cryostat-operator/wiki/Security-and-Authz content) describes Cryostat `POST`ing files to `jfr-datasource` and `cryostat-reports`. This still happens for active recording transfers, but the default configuration for archived recordings is to use a presigned URL for transfer since the archived recording is already present in storage. Cryostat still sends a `POST` to the other components in this case, but the request does not actually contain a JFR binary file - instead it contains a presigned URL from storage which allows the receiver to download the specified asset (and only the specified asset, for a limited time), so that the file does not need to be streamed from storage, through Cryostat, and into the datasource/reports-generator but can be transferred directly. This behaviour can be configured to disable presigned transfers and always go through Cryostat.