[FEATURE] Track consumed params and content in RestRequest

[dbwiddis]

Is your feature request related to a problem?

OpenSearch's RestRequest class tracks whether params and content are "consumed". The apparent motivation for this feature is to permit a "did you mean" capability if you have a typo in a param name.

For this to work properly, we need to track when a param is accessed

What solution would you like?

The "pythonic" equivalent of this Java code in the RestRequest class:
For params:

public final String param(String key) {
    consumedParams.add(key);
    return params.get(key);
}

For content:

public BytesReference content() {
    return content(true);
}

protected BytesReference content(final boolean contentConsumed) {
    this.contentConsumed = this.contentConsumed | contentConsumed;
    return httpRequest.content();
}

What alternatives have you considered?

Just consuming all the content and params, essentially disabling this feature.

Do you have any additional context?

Testing the existence of a param shouldn't consume it. Fetching its value causes this side effect.