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.

yuzu/web_browser: Minor cleanup

gl_rasterizer: Silent unsafe mix warning

file_sys/directory: Remove unused DirectoryBackend class

This isn't used at all, so we can just get rid of it.

Gets rid of a few indirect inclusions.

This is a function that definitely doesn't always have a non-modifying
behavior across all implementations, so this should be made non-const.

This gets rid of the need to mark data members as mutable to work around
the fact mutating data members needs to occur.

Avoids the need to potentially reallocate the contained callbacks.

These currently aren't used by anything other than the QtWebBrowser
class itself, and can be made private.

audio_core: remove unnecessary spaces on comments

game_list: Remove a reference of a reference

settings: Add support for setting the RTC manually

applets: Implement HLE web browser applet (LibAppletOff)

gl_global_cache: Add dummy global cache manager

Stored as signed seconds since epoch.

gl_shader_cache: Use dirty flags for shaders

service/vi: Unstub IApplicationDisplayService's SetLayerScalingMode

qt: Move profile manager to own UI tab

gl_rasterizer_cache: Use GL_STREAM_COPY for PBOs

Since the data is doing the path CPU -> GPU -> GPU copy is the most
approximate hint. Using GL_STREAM_DRAW generated a performance warning
on Nvidia's stack. Changing this hint removed the warning.

service/vi: Correct reported dimensions from IApplicationDisplayService's GetDisplayResolution()

These values are not equivalent, based off RE. The internal value is put
into a lookup table with the following values:

[3, 0, 1, 2, 4]

So the values absolutely do not map 1:1 like the comment was indicating.

Avoids entangling the IPC buffer appending with the actual operation of
converting the scaling values over. This also inserts the proper error
handling for invalid scaling values.

This appears to only check if the scaling mode can actually be
handled, rather than actually setting the scaling mode for the layer.

This implements the same error handling performed on the passed in
values.

Return no application area when games try to open an application area

Proper no message handling for AM::PopMessage

Within the actual service, it makes no distinguishing between docked and
undocked modes. This will always return the constants values reporting
1280x720 as the dimensions.