Improve visuals of inactive fields

[snacks02]

Only root users can edit "Brand" and "Model Name" on the "Edit Model" page, but this isn't obvious without hovering over the fields:

Maybe make them muted like "Evaluation" on the "Add new model" page?:

Think of what to do with "Evaluation" on the "Edit model" page also:

[snacks02]

Both design and code from @MRSallee