Feature suggestion: Configuration for translating non float values into float64

[delley123]

Sometimes a JSON result is not float value. And thus can not be parsed to an float64.
Example error: (msg="Failed to convert extracted value to float64" path={.state} value=GREEN err="strconv.ParseFloat: parsing "GREEN": invalid syntax; strconv.ParseFloat: parsing "GREEN")

It could be great to be able to configure a "translator" value.
Example:

• name: example_global_value
  path: '{ .counter }'
  help: Example of a top-level global value scrape in the json
  labels:
  environment: beta # static label
  location: 'planet-{.location}' # dynamic label
  translate:
  GREEN: "0"
  AMBER: "1"
  RED: "2"