[2.x, Accessibility] Inconsistent save states for fabric/subnet/vlan/space editing

[Maria Vrachni]

[2.2.0rc2, Accessibility] In the networking part of MAAS the forms are not A-level accessible.

A-level accessibility guideline 3.2.2 "Elements do not change when they receive input" is not satisfied in the case of forms in Networking as the forms auto-save the user input.

Bug description:

* Current result:

Given I am Subnets
When I am editing the name, cidr, gateway IP etc
Then I want to see that my changes were saved, but I don't have any feedback from the system

* Expected/ correct result:

Given I am Subnets
When I am editing the name, cidr, gateway IP etc
Then MAAS provides feedback that my changes were saved x time ago

In order to make the forms accessible we either need to introduce a save/cancel button that allows the users to commit or cancel their changes, or introduce visual feedback on the page to communicate to the user that their changes have been saved (example "All changes have been saved" or "Saved 1 sec ago"). In the autosave case, we need to provide information to warn the users that their changes will be saved automatically and it is also good to provide a way to revert to the previous values. Also, research shows that a save button gives security to the users and makes them feel in control.

[UX needed]

[OS X Sierra]

Chrome, 56.0.2924.87 (64-bit)