[TASK] Move workspaces data handling tests to core

The ext:core and ext:workspaces data scenario functional
tests are pairs: core comes with the 'Modify' scenarios
and workspaces extends them with own 'Discard', 'Modify',
'Publish' and 'PublishAll' ones.

The patch separates the ext:core 'Modify' scenarios
into an own directory and moves the ext:workspaces
pendants next to it. This gives better overview and
makes more clear that most of the workspaces related
handling is part of ext:core anyways.

Resolves: #97279
Releases: main
Change-Id: Id20b07c0dcb6818fc6881b37d38f8ee7bae87543
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74152


Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>