feat: archive full dolphin-emu/Sys, add DSP/font/IPL paths to pack

dolphin-emu/Sys/ folder (2562 files) from libretro/dolphin Data/Sys.
retroarch.yml: DSP firmware (dsp_coef.bin, dsp_rom.bin), fonts
(font_western.bin, font_japanese.bin) at dolphin-emu/Sys/GC/ paths.
ref: DolphinLibretro/Boot.cpp:72-73, HW/DSPLLE/DSPHost.cpp,
HW/EXI/EXI_DeviceIPL.cpp. pack: 452 files, 0 missing.

bios/Nintendo/GameCube/dolphin-emu/Sys/Shaders/grayscale2.glsl

@@ -0,0 +1,7 @@
+void main()
+{
+	float4 c0 = Sample();
+	// Info: https://web.archive.org/web/20040101053504/http://www.oreillynet.com:80/cs/user/view/cs_msg/8691
+	float avg = (0.222 * c0.r) + (0.707 * c0.g) + (0.071 * c0.b);
+	SetOutput(float4(avg, avg, avg, c0.a));
+}