[BUGFIX] Use BLOB type column for uc in be_users table

The unified handling for frontend and backend users requires
identical SQL column types to properly escape the input data.
Using binary encoding for the uc column in combination with a
TEXT type field in the BE fails on PostgreSQL.

Resolves: #79451
Related: #79324
Releases: master
Change-Id: I08e404ca7050aa169234a4542ffa640cad2cd1ff
Reviewed-on: https://review.typo3.org/51393


Reviewed-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Tested-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Manuel Selbach <manuel_selbach@yahoo.de>
Tested-by: Manuel Selbach <manuel_selbach@yahoo.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>