Add TransportAction Integ Tests for paginated APIs.

[gargharsh3134]

Is your feature request related to a problem? Please describe

_list/shards API makes use of TransportCatShardsAction to get the list of shards to be responded in a page. Currently, the support of Integration tests which assert the behaviour of TransportCatShardsAction response is missing. This issue tracks the addition of such tests, which would help avoid the unoptimizations like the one called out in (#16448).

Similar tests for _list/indices, would have to be added once the core logic gets transferred from Rest layer to a new CatIndices specific TransportAction

Describe the solution you'd like

Adding integ test support in TransportActions for paginated _list APIs.

Related component

Cluster Manager

Describe alternatives you've considered

No response

Additional context

No response

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