Support `::name` metadata property

Currently we have this legacy template interpolation for `@doc` which will look at the internal properties of the value passed.

```
@doc("{name}", T)
model Foo {}
```
[playground](https://typespec.io/playground?c=QGRvYygie25hbWV9IiwgVCkKbW9kZWwgRm9vPFQgZXh0ZW5kcyB7fT4ge30KCscdQmFyxQ%2FGDlRlc3QgewogIGE6xTdCYXI%2BOwp9&e=%40typespec%2Fopenapi3&options=%7B%7D)

This parameter is broken as it requires to be an object but it looks at the internal type properties(it doesn't actually interpolate the model properties)

We added string interpolation in a goal to remove fill that gap but it doesn't actually cover the only case where the formatArgs parameter did actually work.

We should find a way to have `::name` metadata property that we can use on templates args

```
@doc("${T::name}")
model Foo {}
```