APIv4 - merge ActionUtil with Request::create

[colemanw]

Overview

Consolidates some APIv4 code with v3.

Before

The Request::create function was broken for v4, and ActionUtil had been serving the same purpose but in a non-broken way.

After

Deleted ActionUtil and fixed Request::create to work correctly with v4.

[civibot]

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[colemanw]

Retest this please

[seamuslee001]

@colemanw the test rig is getting tied up on the test suite.

CRM_Utils_API_MatchOptionTest

[colemanw]

@seamuslee001 looks like that was an uncaught exception caused by civicrm_api3_create_success trying to do getfields with no entity.

[seamuslee001]

@colemanw test failures look related

[seamuslee001]

@colemanw latest test failures look related

[colemanw]

@seamuslee001 I got the tests passing by cleaning up all the places where the api wrapper was being used incorrectly, e.g. with missing $params['version'] or null $entity.

[eileenmcnaughton]

Looks like our test cover is working well here - merging now they are passing