Revert "[FEATURE] New TCA type "country""

This reverts commit ad813a0d.

Reason for revert: Post-merge, valid concerns were raised
that may make follow-ups after a sprint release too hard.

The most pressing one being processing via DataHandler and
regarding Record Transformation. For details, see the
currently unresolved comments in the original patch.

A follow-up patch has been created with #104997 which
can start the process on finishing the implementation.

Main points to address:

- DataHandler / Record Transformation (+Tests)
- FlexForm Support
- Possible multi-selection
- Extbase typeconverter implementation so that stored
  relations can be processed in frontend implementations
  of these records

Releases: main
Resolves: #104999
Related: #104997
Reverts: #99911
Change-Id: Ib532b096417d18d89a5695136a28ea594caa518c
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/86152


Reviewed-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Garvin Hicking <gh@faktor-e.de>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Garvin Hicking <gh@faktor-e.de>