Include strings.rc as resource file on Windows

This was included here:
6f546951b4/build/Aegisub/Aegisub.vcxproj.filters (L1094)
in the MSVC build.

src/meson.build

@@ -214,6 +214,7 @@ elif host_machine.system() == 'windows'
                                                  depends: version_h,
                                                  include_directories: [res_inc, version_inc, wx_inc])
     endif
+    aegisub_src += windows.compile_resources('res/strings.rc')
 endif
 
 if conf.has('WITH_FONTCONFIG')