[BUGFIX] Misplaced documentation icon in extension manager

When using EXT:sphinx, the interactive JSON view should take the place of
the always empty SXW view action.

Resolves: #63445
Related: #63430
Releases: master
Change-Id: Ib7f3488ebffb0cc6e6fd5cc0c6c0068c85e0abee
Reviewed-on: http://review.typo3.org/34809
Reviewed-by: Frank Nägler <typo3@naegler.net>
Tested-by: Frank Nägler <typo3@naegler.net>
Tested-by: Xavier Perseguers <xavier@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Alexander Opitz <opitz.alexander@googlemail.com>
Tested-by: Alexander Opitz <opitz.alexander@googlemail.com>