deployment: deploy streaming stack

We need to make sure that our streaming software is deployed to the streaming server.

This includes:
- `kdaectrl`
- `kdaediag`
- `event_aggregator`
- `event_udp_to_kafka`
- `filewriter` (once it is implemented)

Each of these pieces of software may have instrument-specific config files; we need a mechanism to define those config files and make the relevant software use them.

We want the installation steps of this software to be managed via ansible at the top-level.

Start by locating the top-level Ansible deployment entry point and the definitions for kdaectrl, kdaediag, event_aggregator, event_udp_to_kafka, and filewriter. Trace how instrument-specific configuration is currently represented or consumed, if at all. Done means the listed software is installed on the streaming server through Ansible and has a defined mechanism for using instrument-specific configuration files.

Scritto dal modello di indicizzazione a partire dal testo della issue.