InfluxQLQueryApi.queryJson should not transform all values to String

[Willena]

Proposal:
It would be nice if influxQLQueryApi.queryJson() can preserve field types instead of converting everything to Strings.
ValueExtractor should expose an API with raw types.

Current behavior:
Unless a ValueExtractor is present, every values get transformed to String even of the InfluxDB Json result contains a non string value.

Desired behavior:
Unless a value extractor is specified, the JSON result should preserve original response types as much as possible

Alternatives considered:
For now, provide a value extractor that parse each String values.
It works but doing twice the job: for a number value it get read by Gson as Number then the client converts it to String then manually converted to back to a number.

Use case:
All use cases using influxQLQueryApi.