In these cases the system object is nearby, and in the other, the
long-form of accessing the telemetry instance is already used, so we can
get rid of the use of the global accessor.

MSVC does not seem to like using constexpr values in a lambda that were declared outside of it.
Previously on MSVC build the hotkeys to inc-/decrease the speed limit were not working correctly because in the lambda the SPEED_LIMIT_STEP had garbage values.
After googling around a bit I found: https://github.com/codeplaysoftware/computecpp-sdk/issues/95 which seems to be a similar issue.
Trying the suggested fix to make the variable static constexpr also fixes the bug here.

With shader caches on the horizon, one requirement is to provide visible
feedback for the progress. The shader cache reportedly takes several
minutes to load for large caches that were invalidated, and as such we
should provide a loading screen with progress.

Adds a loading screen widget that will be shown until the first frame of
the game is swapped. This was chosen in case shader caches are not being
used, several games still take more than a few seconds to launch and
could benefit from a loading screen.

This allows us to present a much nicer UI to the user over a simple combo box and is made easy with the modular nature of the profile-selection applet frontend.

Using the QtProfileSelectorDialog, this implementation is trivial. This mimics the real switch behavior of asking which user on every game boot, but it is default disabled as that might get inconvenient.

Allows capturing screenshot at the current internal resolution (native for software renderer), but a setting is available to capture it in other resolutions. The screenshot is saved to a single PNG in the current layout.

Presents profiles in a list, similar to switch.

We can just return a new instance of this when it's requested. This only
ever holds pointers to the existing registed caches, so it's not a large
object. Plus, this also gets rid of the need to keep around a separate
member function just to properly clear out the union.

Gets rid of one of five globals in the filesystem code.

file_sys/registered_cache: Use regular const references instead of std::shared_ptr for InstallEntry()

These parameters don't need to utilize a shared lifecycle directly in
the interface. Instead, the caller should provide a regular reference
for the function to use. This also allows the type system to flag
attempts to pass nullptr and makes it more generic, since it can now be
used in contexts where a shared_ptr isn't being used (in other words, we
don't constrain the usage of the interface to a particular mode of
memory management).

a

Allows the game to verify and send a message to the frontend.

Allows using Qt provider over default.

Prevents unnecessary reloads on every configuration operation.

Opens a new file manager window at the UserDir.

* get rid of boost::optional

* Remove optional references

* Use std::reference_wrapper for optional references

* Fix clang format

* Fix clang format part 2

* Adressed feedback

* Fix clang format and MacOS build

Now that we can actually use std::optional on macOS, we don't need to
continue using boost::optional here.

We shouldn't silently continue if loading failed, since the general
assumption is that no messages showing up implicitly indicates success.