[!!!][TASK] Simplify TCA authMode settings

To prepare towards a deployable backend group access
rights system, some of the more obscure options are
removed to reduce overall complexity.

* TYPO3_CONF_VARS['BE']['explicitADmode'] is finally
  gone: Following a deny list approach is a flawed security
  system. TYPO3's default setting (explicitADmode=allow)
  follows the very common "Least Privileged" principle,
  so editors need to be explicitly given access to a
  CType, as is done with all other permissions.

* The only valid value for TCA config option "authMode"
  on type="select" fields is now "explicitAllow". The
  previous "explicitDeny" value is abandoned following
  the reasoning above. The value "individual" is abandoned
  since it is a very rarely used setting (not a single
  match in TER).

* With authMode="individual" being gone, the select item
  array keys on position six that could be set to "EXPL_DENY"
  and "EXPL_ALLOW" are obsolete.

* Field "explicit_allowdeny" in table be_groups is
  simplified. This was a comma separated list of
  colon separated: "table:field:value:ALLOW/DENY".
  The last "ALLOW" or "DENY" is now obsolete.

The patch removes the above handling from the core. A
TCA migration scans TCA for invalid options and adapts
them. An upgrade wizard is in place to clean up the
be_groups explicit_allowdeny field of existing rows.

Resolves: #97265
Releases: main
Change-Id: I545b08fc694e9081ad79e69e7f55f684316e7b0f
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74126


Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Benni Mack <benni@typo3.org>