Replace settings save functionality with simple toast messages

Problem

Currently our flow of saving a setting, actually involves pressing the save button. To make it worse, often the save button is out of view. This feels old and redundant and should be automated, for a more efficient flow which gives the user more confidence.

This becomes especially visible in the auto devops demo: https://youtu.be/AgKc_KUQEtE

Proposal

Replace settings save functionality with simple temporary toast messages.

• This will need us figuring out the banner/toast usage/paradigm

cc: @tauriedavis @sarrahvesselov @mydigitalself