Alliance Changes Should Trigger a Vote by Members

This would definitely be a great quality of life feature, when playing with AI I tend to avoid alliances purely for this reason, I'll be working hard to balance my friendships with all the other civilizations and then bam, suddenly I'm at war, so I can either anger one side by going to war with them, or anger my allies for breaking the alliance. Looking at the Federation features in Stellaris would, I feel, be a good starting point for how it might work.