- #6662
- users can now provide a `name` or `data-valmsg-for` attribute to avoid `ArgumentException`s
- affects `<input>`, `<select>`, `<textarea>` elements and validation message `<div>`s
- remove `fullName` check in `DefaultHtmlGenerator.GetCurrentValues(...)` entirely
The new workaround is _not_ identical to changing `ViewData.TemplateInfo.HtmlFieldPrefix`
- does not change where expression values are found in `ModelState` or `ViewData`
- likely needs to be combined with additional workarounds i.e. for advanced use only
nits:
- clean up some excessive argument naming; add a few missing argument names
- take VS suggestions in changed classes e.g. inline a few variable declarations
- clean up some test data
