[TASK] Move 'extension download' upgrade wizard to EM

The install tool has just a few dependencies to
ext:extensionmanager. Most notably, it ships the
AbstractDownloadExtensionUpdate upgrade wizard,
which is used when core extracts stuff to dedicated
extensions that are removed from monorepo.

The v12 upgrade wizard for 'fe_login_mode' uses this.

These upgrade wizards are tailored for non-composer-mode
only, just like the extensionmanager, which essentially
does nothing in composer mode.

To loosen the dependency from ext:install to
ext:extensionmanager, the patch moves the abstract, a
model class for this case, plus the fe_login_mode
implementation to ext:extensionmanager.

Class aliases are established, so a casual deprecation
is enough in this case. A few extensions rely on the
class, typically those that try to extend the upgrade
range of core by forward porting wizards older than
two major core versions. Those shoud continue to work
with v13, and will have to adapt the class namespace
of the abstract with v14 latest.

Moving the fe_login_mode wizard around does not make the
wizard show up again in case the wizard has been marked
'done' during v12 upgrade already, since usually the
according DB field does not exist anymore. We don't need
special handling for this case.

Resolves: #102943
Releases: main
Change-Id: Idb5e6c90900ffad7f9c3c383fff58a05c6728aa9
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/82659


Tested-by: Andreas Kienast <a.fernandez@scripting-base.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Nikita Hovratov <nikita.h@live.de>
Reviewed-by: Andreas Kienast <a.fernandez@scripting-base.de>
Reviewed-by: Nikita Hovratov <nikita.h@live.de>