Make sure confidence level is always between 0 and 100

[labo-flg]

issue

Following #4304, we need to make sure that the value saved in the platform for any max_confidence fields (user, groups) are always between 0 and 100.

We cannot enforce this in the schema mapping in elastic, so we need to check this in the backend code:

test cases

This can only be tested through API calls, the UI already crop the value between 0 and 100.
This concerns operations:

• user add/edit
• group add/edit

Attention, edition can be plain object value, or field patch with only the max_confidence and corresponding object_path.

Example with edit group:

{
  "id": "00b4e453-40e2-451d-8c32-09fd0532d80f",
  "input": {
    "key": "group_confidence_level",
    "object_path": "group_confidence_level/max_confidence",
    "value": 45
  }
}

{
  "id": "00b4e453-40e2-451d-8c32-09fd0532d80f",
  "input": {
    "key": "group_confidence_level",
    "value": {
      "max_confidence": 45,
      "overrides: []
    }
  }
}