[TASK] Cleanup DataHandler functional tests

Some DataHandler functional test cases are duplicated or are not
required anymore. Here's a list of what has changed and moved
into some existing testing structure:

Core:
* DataHandlerTest::canCreateTtContent
** Regular\Modify\ActionTest::createContents
* DataHandlerTest::canLocalizeTtContent
** Regular\Modify\ActionTest::localizeContent
* DataHandlerTest::canCopyPasteTtContent
** Regular\Modify\ActionTest::copyPasteContent
* DataHandlerTest::canCutPasteTtContent
** Regular\Modify\ActionTest::movePasteContentToDifferentPage
* IRRE\MtoNMMAsymetricLocalizationKeepTest::*
** IRRE\CSV\Modify\ActionTest::localizeParentContent*
** IRRE\ForeignField\Modify\ActionTest::localizeParentContent*
* IRRE\MtoNMMAsymetricLocalizationSelectTest::*
** IRRE\CSV\Modify\ActionTest::localizeParentContent*
** IRRE\ForeignField\Modify\ActionTest::localizeParentContent*

Workspaces:
* IRRE\MToNMMTest::*
** ManyToMany\Modify\ActionTest::*
** ManyToMany\Publish\ActionTest::*
** ManyToMany\PublishAll\ActionTest::*
* IRRE\OneToNCSVTest::*
** IRRE\CSV\Modify\ActionTest::*
** IRRE\CSV\Publish\ActionTest::*
** IRRE\CSV\PublishAll\ActionTest::*
* IRRE\OneToNForeignFieldTest::*
** IRRE\ForeignField\Modify\ActionTest::*
** IRRE\ForeignField\Publish\ActionTest::*
** IRRE\ForeignField\PublishAll\ActionTest::*

Resolves: #58870
Releases: 6.2
Change-Id: I0c75fcf826d05f8515a5609cb00c153992ba7b44