graphics: custom full screen resolution (#274)

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

## Description of change
Adds a new option to forcibly set the full screen resolution.

Same idea as -windowscale.

## Compiling
🔺 

## Testing
Seems to be showing similar results as -windowscale:

* Works GREAT for IIDX/SDVX
* popn launches at correct resolution but only draws a small image (at
native res) - can be scaled with F11 menu
* nostalgia is broken in weird ways, image is drawn correctly but bottom
`credits` text draws at wrong offset, game's wintouch logic broken
(perhaps expectedly)

## Other notes
In theory this could enable "play sdvx in landscape mode" option but the
image scaling doesn't quite work with extreme values.

src/spice2x/launcher/launcher.cpp

@@ -102,6 +102,7 @@
 #include "util/sysutils.h"
 #include "util/tapeled.h"
 #include "util/time.h"
+#include "util/utils.h"
 #include "avs/ssl.h"
 #include "nvapi/nvapi.h"
 #include "hooks/graphics/nvapi_hook.h"
@@ -366,6 +367,15 @@ int main_implementation(int argc, char *argv[]) {
         GRAPHICS_FORCE_SINGLE_ADAPTER = false;
     }
 
+    if (options[launcher::Options::FullscreenResolution].is_active()) {
+        std::pair<uint32_t, uint32_t> result;
+        if (parse_width_height(options[launcher::Options::FullscreenResolution].value_text(), result)) {
+            GRAPHICS_FS_CUSTOM_RESOLUTION = result;
+        } else {
+            log_warning("launcher", "failed to parse -forceres");
+        }
+    }
+
     if (options[launcher::Options::spice2x_NvapiProfile].value_bool() && !cfg::CONFIGURATOR_STANDALONE) {
         nvapi::ADD_PROFILE = true;
     }
@@ -952,12 +962,9 @@ int main_implementation(int argc, char *argv[]) {
         GRAPHICS_WINDOW_STYLE = options[launcher::Options::spice2x_WindowBorder].value_uint32();
     }
     if (options[launcher::Options::spice2x_WindowSize].is_active()) {
-        auto s = options[launcher::Options::spice2x_WindowSize].value_text();
-        uint32_t w, h;
-        const auto remove_spaces = [](const char& c) { return c == ' '; };
-        s.erase(std::remove_if(s.begin(), s.end(), remove_spaces), s.end());
-        if (sscanf(s.c_str(), "%u,%u", &w, &h) == 2) {
-            GRAPHICS_WINDOW_SIZE = std::pair(w, h);
+        std::pair<uint32_t, uint32_t> result;
+        if (parse_width_height(options[launcher::Options::spice2x_WindowSize].value_text(), result)) {
+            GRAPHICS_WINDOW_SIZE = result;
         } else {
             log_warning("launcher", "failed to parse -windowsize");
         }