Selection regressions compared to MVC 5

[dougbu]

1. current code ignores null values in a collection. this means a SelectListItem with Value = string.Empty or (for tag helpers) an <option value="">Some text</option> element will not match and they should. (problem occurs because defaultValues.OfType<object>() is not the correct translation of from object value in defaultValues)
2. if generated <option/>s use enum names, they will never match int values found in ViewData (decimal values may match but that'll be ignored)

there's probably more...

[dougbu]

self-assigning and adding to current milestone per offline discussions

[dougbu]

9ac6ebd