Bug 1907000 - fix Add entry drag n drop.
* Added a new class to force the pointer cursor. * Added this class to the Add entry anchors. * Added a data flag to assist spotting the drag n drop activity when Add entry is the element clicked for dragging the block. * Added js to test this data flag before submitting on click. * Renamed `AddNewPostShortcut()` in recent/tagged posts JS to better identify them. Change-Id: I3e367cd9323e9eb5ef18495d33ce6fa9c3c7c48d