…bolinks

Turbo requires that redirects returned by form submissions have a status of
303 (see other) so that the browser will follow them with a GET request and
not use the HTTP method of the submission request. This is semantically
correct, but a change in behavior from how Rails UJS handled things.

Additionally, Turbo will not render anything when a 200 response is returned
by a form submission, instead requiring that a 422 (unprocessable entity)
status is returned in order for it to render the new HTML and its validation
error messages. This is going to become the Rails default in the future.

There was previously a single controller and set of views that handled
all note CRUD for both Member and Item. As a part of reworking this
code, I created separate controllers and views for the notes on each of
these models. I think this will be eaiser to understand and will allow
the notes placed on each model to diverge more easily.