LPS-48749 Add new getStagingGroup helper method
LPS-48749 Remove throws part, we are not throwing any exception
LPS-48749 Add GroupDisplayContextHelper in order to help in Group related calculations and logic
LPS-48749 Update LayoutsAdminDisplayContext accordingly
LPS-48749 Update DefineObjectTag for staging tag library. While the group getting from request happens to be the same as the LayoutsAdmin related, but these are essentially different components so they might go into different directions later. Retain logic in the tag for now.
LPS-48749 Prevent NPE
LPS-48749 Based on the getGroup() implementation when the getGroup() returns null the getLiveGroup() also returns null, so this call is not necessary
LPS-48749 exceptions no longer thrown
LPS-48749 Regen