Add Borealis GUI for patch extraction on Switch.

Replace the console UI with a Borealis-based flow, bundle ROMFS assets and
borealis as a submodule, and apply small upstream patches at build time.
Self-delete runs after romfsExit on quit so the NRO can be removed like the
old console build.

patches/borealis-swkbd-libnx.patch

@@ -0,0 +1,12 @@
+--- a/library/lib/platforms/switch/swkbd.cpp
++++ b/library/lib/platforms/switch/swkbd.cpp
+@@ -39,7 +39,9 @@ static SwkbdConfig createSwkbdBaseConfig(std::string headerText, std::string sub
+     swkbdConfigSetSubText(&config, subText.c_str());
+     swkbdConfigSetStringLenMax(&config, maxStringLength);
+     swkbdConfigSetInitialText(&config, initialText.c_str());
++#if defined(SWKBD_CONFIG_SET_STRING_LEN_MAX_EXT)
+     swkbdConfigSetStringLenMaxExt(&config, 1);
++#endif
+     swkbdConfigSetBlurBackground(&config, true);
+ 
+     return config;