[receiver/elasticsearch]: add missing datapoints for operation count and operation time metrics

[aboguszewski-sumo]

Description:
All missing datapoints for metrics elasticsearch.index.operation.count and elasticsearch.index.operation.time have been added. This PR also replaces the following PRs: #14871 #14921 #14924
The rationale for this PR is explained here: #14924 (comment)

Link to tracking Issue: #14635

Testing:
Unit and integration tests

Documentation:
mdatagen

[djaglowski]

I initially thought this should be a bug fix because it appeared that we had missed a data point or two on an existing metric. However, I do not think adding 30+ data points to a metric is in the spirit of "fixing a mistake".

I do think that adding these is fine, but we should declare it an enhancement and use a feature gate.

[aboguszewski-sumo]

To be honest, all of these datapoints aren't necessary for me (only some arbitrarily chosen ones), but operations metrics are probably the most "basic" metrics there can be, so it might be a good idea to at least send these with a full set of datapoint.
Because this PR is not a heavy blocker, I'll wait with changes for #14875 to get merged, as some code related to feature gates will be common for both PRs.

[aboguszewski-sumo]

@djaglowski I added feature gates.