Add @var to Pager classes

Add @var to Pager classes

Some are needed to make better results with phan in extensions

For example:
File CentralNoticeCampaignLogPager.php line 12:
Assigning array{0:20,1:50,2:100} to property but
\CentralNoticeCampaignLogPager->mLimitsShown is
array{0:20,1:50,2:100,3:250,4:500}
[PhanTypeMismatchProperty]

With "@var int[]" the type is correct

Change-Id: Ic68910bf17344852ad11fcc000a47891e4bf0179