We were manually generating the IDs in order to pass them as data
attributes in the HTML in a component where we don't have access to the
form which has the inputs.
However, these data attributes only make sense when there's a form
present, so we can pass the form as a parameter and use it to get the
IDs.
We can now define a map as editable when there's an associated form,
which makes sense IMHO.
We're going to make a change, and it's easier if we've already got a
component with tests so we don't have to write system tests to check
whether the map is rendered.
