Simplify jsonapi test suite.

lib/classes/JsonApi/Errors/ErrorHandler.php

tests/_support/Helper/Jsonapi.php

tests/_support/_generated/JsonapiTesterActions.php

tests/jsonapi/ActivityStreamShowTest.php

tests/jsonapi/BlubberCommentsByThreadIndexTest.php

tests/jsonapi/BlubberCommentsCreateTest.php

tests/jsonapi/BlubberCommentsDeleteTest.php

tests/jsonapi/BlubberCommentsShowTest.php

tests/jsonapi/BlubberCommentsUpdateTest.php

tests/jsonapi/BlubberMentionsRelationshipTest.php

tests/jsonapi/BlubberTestHelper.php

tests/jsonapi/BlubberThreadsCreateTest.php

tests/jsonapi/BlubberThreadsIndexTest.php

tests/jsonapi/CommentsShowTest.php

tests/jsonapi/WikiShowTest.php