LPS-39405 Initial source formatting
LPS-39405 Move the Add Layout permission logic to Permission Util
LPS-39405 Remove redundant logic in add layout permission checking
LPS-39405 If current layout is a child page, check add layout permission to current layout
LPS-39405 Rearrange code in add panel (no logic changes)
LPS-39405 Use same condition to display the add icon and the add panel
LPS-39405 Use same condition to display add application and add content tab.

Initial conditions to display the add content and add application tabs are the same. In both cases the user adds an application to a page. Specific conditions (e.g. view permissions, add to page permissions, create content permissions) are checked within the panel logic.
LPS-39405 Display the add layout panel based on the add layout permission
LPS-39405 SF