After working with the previous change in
https://github.com/astral-sh/ruff/pull/7821 I found the names a bit
unclear and their relationship with the user-facing API muddied. Since
the applicability is exposed to the user directly in our JSON output, I
think it's important that these names align with our configuration
options. I've replaced `Manual` or `Never` with `Display` which captures
our intent for these fixes (only for display). Here, we create room for
future levels, such as `HasPlaceholders`, which wouldn't fit into the
`Always`/`Sometimes`/`Never` levels.
Unlike https://github.com/astral-sh/ruff/pull/7819, this retains the
flat enum structure which is easier to work with.