sdvx: landscape mode (#277)

## Link to GitHub Issue, if one exists
n/a

## Description of change
Add `SDVX Landscape Mode` option, allowing you to play SDVX in landscape
monitor orientation, with black borders on left and right - similar to
how EAC does it. This is meant to be an alternative to what people do
today, which is launching in windowed mode.

By default, with just `-sdvxlandscape` enabled, EG will launch at
1920x1080 (transposed from the original 1080x1920 resolution).

It is possible to combine with `-forceres` to launch at higher
resolutions. At some point though, when rendering at large resolutions
past 1440p, at some point scaling may break due to #276.

Disabled on 32-bit SDVX since dx9 `CreateDeviceEx` call is required;
`CreateDevice` won't work. For the same reason this isn't being made a
generic option for museca/rb/etc. In theory you can supply
`-sdvxlandscape` to games like IIDX and play landscape games in portrait
mode, although again, scaling my break due to #276.

Also, add new options (bottomleft/right) for subscreen overlay position
so that they don't overlap with the main screen in landscape mode.

## Compiling
🙂

## Testing
Tested a couple versions of VW and EG.

src/spice2x/hooks/graphics/graphics.h

@@ -36,6 +36,7 @@ extern std::optional<int> GRAPHICS_FORCE_VSYNC_BUFFER;
 extern bool GRAPHICS_FORCE_SINGLE_ADAPTER;
 extern bool GRAPHICS_PREVENT_SECONDARY_WINDOW;
 extern std::optional<std::pair<uint32_t, uint32_t>> GRAPHICS_FS_CUSTOM_RESOLUTION;
+extern bool GRAPHICS_FS_FORCE_LANDSCAPE;
 
 extern graphics_dx9on12_state GRAPHICS_9_ON_12_STATE;
 extern bool GRAPHICS_9_ON_12_REQUESTED_BY_GAME;