Resolve "Service ping integration - Index inconsistencies"

What does this MR do and why?

This merge request aims to collect a list of missing indexes via service ping.

To generate the files I have used the following commands:

bin/rails generate gitlab:usage_metric IndexInconsistencies --type generic

bin/rails generate gitlab:usage_metric_definition index_inconsistencies_metric --class_name=IndexInconsistenciesMetric --dir=settings

The IndexInconsistenciesMetric returns a array of hashes. Example:

[
  {
     object_name: 'index_1', type: 'wrong_index',
     object_name: 'index_2', type: 'missing_index',
     ....
  }
]

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #390273 (closed)