#### ⚠️ targets #10051
## Summary of the Pull Request
This updates our `ThrottledFunc`s to take a dispatcher parameter. This means that we can use the `Windows::UI::Core::CoreDispatcher` in the `TermControl`, where there's always a `CoreDispatcher`, and use a `Windows::System::DispatcherQueue` in `ControlCore`/`ControlInteractivity`. When running in-proc, these are always the _same thing_. However, out-of-proc, the core needs a dispatcher queue that's not tied to a UI thread (because the content proces _doesn't have a UI thread!_).
This lets us get rid of the output event, because we don't need to bubble that event out to the `TermControl` to let it throttle that update anymore.
## References
* Tear-out: #1256
* Megathread: #5000
* Project: https://github.com/microsoft/terminal/projects/5
## PR Checklist
* [x] This is a part of #1256
* [x] I work here
* [n/a] Tests added/passed
* [n/a] Requires documentation to be updated
## Detailed Description of the Pull Request / Additional comments
Fortunately, `winrt::resume_foreground` works the same on both a `CoreDispatcher` and a `DispatcherQueue`, so this wasn't too hard!
## Validation Steps Performed
This was validated in `dev/migrie/oop/the-whole-thing` (or `dev/migrie/oop/connection-factory`, I forget which), and I made sure that it worked both in-proc and x-proc. Not only that, _it wasn't any slower_!This reverts commit 04b751faa7.
This commit introduce three new `til` features:
* "til/latch.h": A std::latch clone, until we're on C++20.
* "til/mutex.h": A safe mutex wrapper, which only allows you access to the protected data after locking it. No more forgetting to lock mutexes!
* "til/throttled_func.h": Function invocation throttling used to be available as the `ThrottledFunc` class already. But this class is vastly more efficient and doesn't rely on any WinRT types.
This PR also adds a `til::ends_with` string helper which is `til::starts_with` counterpart.
## Validation Steps Performed
* Scrollbar throttling still works as it used to ✔️
* No performance regressions when printing big.txt ✔️Closes#10393
