IA Pages - automatically save single fields

@russellholt @jdorweiler @jbarrett 

Each field is now saved on focusout and on enter kepress (or on delete button click, in the case of example queries).
I also removed the save button, since it's not used anymore.

It needs more refinement, but I wanted to open the PR so you can start reviewing the code, if you want.
@russellholt Ok, I'll make the save endpoint return that value. It will be faster for sure!
Thanks for the suggestions!