Move 'body' parameters to new typed parameters

[b-deam]

As part of the ES client upgrade to 8.x, all client method's now expose the JSON
body' field as typed parameters,, and the use of the body parameter is deprecated.

For example:

client.search(
    index="test-index",
    size=10,
    body={
        "runtime_mappings": {
            "day_of_week": {
                "type": "keyword",
                "script": "emit(doc['@timestamp'].value.dayOfWeekEnum)"
            }
        },
        "aggs": {
            "day_of_week_count": {
                "value_count": {
                    "field": "day_of_week"
                }
            }
        }
    }
)

Would become:

client.search(
    index="test-index",
    size=10,
    runtime_mappings={
        "day_of_week": {
            "type": "keyword",
            "script": "emit(doc['@timestamp'].value.dayOfWeekEnum)"
        }
    },
    aggs={
        "day_of_week_count": {
            "value_count": {
                "field": "day_of_week"
            }
        }
    }
)

We need to refactor all of our runners (and custom runners in rally-tracks) to use these new parameters.

[pquentin]

Another option here is to use **body instead of body.

[b-deam]

Looks like a decision was made to un-deprecate the removal of the body param.

Closing this one out for now.