Feature: #94765 - Introduce showNewRecordLink option

Description

Previously, it was not possible to disable the "new record" link in TCA inline elements, without simultaneously also disabling either the "+" button in each inline records' header (using ['appearance']['enabledControls']['new']) or all other "level links" (using ['appearance']['levelLinksPosition'] = 'none').

To allow integrators to disable this link without any further side effects, the option showNewRecordLink has been introduced to TCA type inline.

With this introduction, the already mentioned ['appearance']['enabledControls']['new'] option does from now on only manage the display of the "+" button of each inline record and does not longer affect the "New record" link.

Furthermore the ['appearance']['levelLinksPosition'] option does no longer support none as value. This option should only be used to position the level links, not to hide them. This can be achieved by setting the corresponding link specific options showAllLocalizationLink, showSynchronizationLink and showNewRecordLink to false. A TCA migration is in place, replacing all TCA configurations, using the ['appearance']['levelLinksPosition'] option with none as value and showing where code adaptations need to take place.

If not set, the new showNewRecordLink option defaults to true.

An example to disable the "New record" button:

'inlineField' => [
    'label' => 'Inline without New record link',
    'config' => [
        'type' => 'inline',
        'appearance' => [
            'showNewRecordLink' => false,
        ],
    ],
],

Impact

It's now possible to disable the "New record" link of TCA inline elements without any side effects.