[Blazor] Support for primitive types in [SupplyParameterFromForm]

[javiercn]

• Adds support for binding IParsable values and Nullable values.

FormDataMapper is the entry point for mapping form values into a type, it receives a FormDataReader and FormDataMapperOptions. The options contain an internal collection of converters and factories that are used to define how to bind a given type.

For well-known types we prepopulate the list of converters.

• FormDataConverter <-> ModelBinder.
• FormDataConverterFactory <-> ModelBinderProvider

#46688 (comment)

Some basic benchmark data against MVC. Beware that this is with any of the main optimizations.

Method	Mean	Error	StdDev	Op/s	Ratio	RatioSD	Gen 0	Gen 1	Gen 2	Allocated
ModelBinding_PrimitiveTypes_Mvc	43.08 μs	1.120 μs	3.141 μs	23,212.5	1.00	0.00	-	-	-	3 KB
ModelBinding_PrimitiveType_Components	25.11 μs	0.834 μs	2.367 μs	39,821.0	0.59	0.07	-	-	-	2 KB

[MackinnonBuck]

Just a couple questions but this looks great to me.

[MackinnonBuck]

Do we have an issue tracking the remaining error handling work? I couldn't find one.

[javiercn]

It's covered as part of #46688

[MackinnonBuck]

Is type ever going to be different from typeof(T)?

[javiercn]

It's not obvious yet in this PR, but it's passed in for a different reason. When you do typeof(T) the generated code needs to ask the type system at runtime (this is in IL) for the type instance, which involves a lookup. For that reason, many serializers cache and pass the type instance along.

If you look at System.Text.Json, they do something similar. See here

The other part is that we might still need this if in the future we want to support polymorphic binding or enable people to do so, so we can't just assume typeof(T) == type in general.