Add device metadata to scan_info

Closes #2705 (closed)

This MR is about to provide metadata per device to the scan_info.

For now it will only provide basic types for few devices:

• Lima
• MCAs

scan_info = {
    ...
    "devices": {
        "1001:mca1" {
            "type":"mca" 
            "channels": [...]
        }
        "1002:lima1" {
            "type":"lima" 
            "channels": [...]
        }
    }
}

With that we now can follow this implicit rules:

"mca" device type
└── channel 1D are spectra

"lima" device type
├── There is a single channel 1D, that's the image detector (we can't assume its name cause of the alias)
├── "bpm" device name
|   └── there is probably something to say here 
├── "roi_counters" device name
|   └── channels are ROIs
├── "roi_profiles" device name
|   └── channels are profile ROIs
└── "roi_collection" device name
    └── there is probably something to say here

Todo

• How to retrieve the metadata?
  • device.get_metadata()?
  • acq_obj.fill_meta()?
    • fill_meta_at_scan_start (which is meta after prepare)
    • fill_meta_at_scan_end (which is meta after the scan)
  • I would be happy to have meta at start of the scan + plus meta after prepare
• When to retrieve the metatdata?
• Update the documentation
• Update the changelog