Mutation helper

[kevinhughes27]

part of #750

• Adds a common mutationHelper and changes all mutations to go through it
• Adds a confirm handler which shows a modal containing the message and a confirm button to re-submit the mutation witn confirm=true

Thoughts

• is there a better way to do Form than mutation and mutationInput
• documentation? I feel like the hierarchy of some of the frontend abstractions is not clear