System: Add a new throttler/pacer which can catch up on lost time

This can result in worse frame pacing, so if you have a decent machine
you'll probably want to turn on "display all frames" in display
settings.

But, it's sadly needed for Android.

android/app/src/cpp/android_host_interface.cpp

@@ -452,7 +452,10 @@ void AndroidHostInterface::EmulationThreadLoop(JNIEnv* env)
     // simulate the system if not paused
     if (System::IsRunning())
     {
-      System::RunFrame();
+      if (m_throttler_enabled)
+        System::RunFrames();
+      else
+        System::RunFrame();
 
       if (m_vibration_enabled)
         UpdateVibration();

android/app/src/main/res/values/strings.xml

@@ -200,4 +200,6 @@
     <string name="settings_summary_game_directories">Change the list of directories used to search for games.</string>
     <string name="game_directories_scanning_subdirectories">Scanning subdirectories.</string>
     <string name="game_directories_not_scanning_subdirectories">Not scanning subdirectories.</string>
+    <string name="settings_display_all_frames">Display All Frames</string>
+    <string name="settings_summary_display_all_frames">Enable this option will ensure every frame the console renders is displayed to the screen, for optimal frame pacing. If you are having difficulties maintaining full speed, or are getting audio glitches, try disabling this option.</string>
 </resources>

android/app/src/main/res/xml/advanced_preferences.xml

@@ -94,6 +94,12 @@
         app:defaultValue="MMap"
         app:summary="@string/settings_summary_cpu_recompiler_fastmem"
         app:iconSpaceReserved="false" />
+    <SwitchPreferenceCompat
+        app:key="Display/DisplayAllFrames"
+        app:title="@string/settings_display_all_frames"
+        app:defaultValue="false"
+        app:summary="@string/settings_summary_display_all_frames"
+        app:iconSpaceReserved="false" />
     <ListPreference
         app:key="Display/MaxFPS"
         app:title="@string/settings_presented_frame_limit"