Fixes#10019. When bulk editing subfields, such as a field within a
group, changes are not persisted to the database. Not only this, but
nested fields with the same name as another selected field are
controlled by the same input. E.g. typing into one fields changes the
value of both.
The root problem is that field paths are incorrect.
When opening the bulk edit drawer, fields are flattened into options for
the field selector. This is so that fields in a tab, for example, aren't
hidden behind their tab when bulk editing. The problem is that
`RenderFields` is not set up to receive pre-determined field paths. It
attempts to build up its own field paths, but are never correct because
`getFieldPaths` receives the wrong arguments.
The fix is to just render the top-level fields directly, bypassing
`RenderFields` altogether.
Fields with subfields will still recurse through this function, but at
the top-level, fields can be sent directly to `RenderField` (singular)
since their paths have already been already formatted in the flattening
step.
Consolidates all bulk edit related tests into a single, dedicated suite.
Currently, bulk edit tests are dispersed throughout the Admin > General
and the Versions test suites, which are considerably bloated for their
own purposes. This made them very hard to locate, mentally digest, and
add on new tests. Going forward, many more tests specifically for bulk
edit will need to be written. This gives us a simple, isolated place for
that.
With this change are also a few improvements to the tests themselves to
make them more predictable and efficient.
