[TASK] Remove class.* from /typo3/

Removes last few class file wrappers from /typo3/ folder.
Those files were renamed and moved during namespacing.

Few references are adapted in comments only.
- Please also see removed require_once statement.

Change-Id: I25a33aea5adde12ce1bca35e1473ccc1d6ed41b0
Resolves: #48942
Releases: 6.2
Reviewed-on: https://review.typo3.org/21284
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Philipp Gampe
Tested-by: Philipp Gampe
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring
[TASK] Page module edit icon for language overlay

Page modules brings multiple views to work with multi-language
content: columns / language / quick. In columns mode a single
translation can be fixated by "language" drop down.

Adds ability to edit language overlay record in column view
with only one language.

Change-Id: I04594461cad4c8e4a0a296111c1a4c40e3263b4c
Resolves: #39107
Releases: 6.2
Reviewed-on: https://review.typo3.org/13599
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
[TASK] Remove dummy files from ext:wizard_crpages and wizard_sortpages

* Remove dummy files
* Rename old class names to the new ones

Change-Id: I77ea8d6a48d10bc56031231a00999655cbecb487
Resolves: #48155
Related: #47756
Releases: 6.2
Reviewed-on: https://review.typo3.org/20765
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring