[BUGFIX] Remove wrongly introduced showNewRecordLink property

With #82489 a condition, introduced in #71918, was changed as
it misused the `['appearance']['enabledControls']['new']` property
to hide the newRecordLink button while actually only the "new" button
of inline records controls should be hidden.

To provide the possibility to hide the newRecordLink, independent
of the controls, a new property `showNewRecordLink` was introduced.

This new property is however superfluous as the newRecordLink button
can already be hidden by setting `['appearance']['levelLinksPosition']`
to `none`.

Therefore the newly introduced `showNewRecordLink` property along
with the condition is removed and the RST is updated and moved to
the correct directory.

Resolves: #92397
Relates: #82489
Releases: master, 10.4
Change-Id: I49cf98c98a9df125f4fbf1737ccdacbf915fb683
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/65846


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>