Revert "[TASK] Move t3lib/stddb files to ext:core"

This reverts commit ef90adcee123ebc2d47c94380cc75e26c176668a

Change-Id: I96ed7987e90addfeb44afe9577ee58ff5dab3344
Related: #45107
Related: #45220
Reviewed-on: https://review.typo3.org/18247
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Revert "[TASK] Move t3lib/stddb/DefaultConfiguration.php to EXT:core"

This reverts commit cf59e1fddac01541ec78df0e646f8dd23b94630c

Change-Id: I11adda17c2ae9cebd16ca14403205f7e38e1b6cb
Related: #45107
Related: #45188
Reviewed-on: https://review.typo3.org/18248
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn