Followups from the new C++/WinRT

Interesting things we could do after #14869 landed:

```[tasklist]
### Tasks
- [x] remove all `InitializeComponent` calls - they do it automatically
- [ ] use `std::optional`<->`IReference` automatic binding
- [x] use `std::format` support (!) for json/uri/hostname/http stuff/all `IStringable`s
- [ ] potentially move to `/await:strict` for C++20 coroutines
```

Review the remaining unchecked tasks in this issue and the changes from #14869, focusing on the C++/WinRT bindings and C++20 coroutine settings. Done means resolving the std::optional/IReference binding follow-up and determining whether /await:strict can be adopted.

Written by the indexing model from the issue text.