Add field in metadata feederinfos section to specify kind of measurement

[So-Fras]

• Do you want to request a feature or report a bug?
  Feature (enhancement)

• What is the current behavior?

In the SLD metadata JSON file, a list of feederInfos is to be found.

"feederInfos" : [ {
    "id" : "id_example_ARROW_REACTIVE",
    "equipmentId" : "equipment-id-example"
  },  ...
]

In order to get the type of the measurement, the user currently has to parse the id to get the "ARROW_REACTIVE" piece of information.

• What is the expected behavior?

A field should be added to store the type of measurement.

"feederInfos" : [ {
    "id" : "id_example_ARROW_REACTIVE",
    "equipmentId" : "equipment-id-example"
    "type" : "ARROW_REACTIVE"
  },  ...
]

• What is the motivation / use case for changing the behavior?
  This would improve the accessibility of this piece of information.