Summarize what required fields still need to be filled in on the create container page

[gashcrumb]

Right now we indicate required fields with a yellow border, might also be good to list required fields above the selected profile list so the user has another visual clue that there's outstanding fields before the create container button can be clicked.

Also maybe 'Default' isn't a good tab name, maybe it should be 'Common' instead as what's in the 'Default' tab is settings that users would commonly need to set (see what I did there?)