Build widgets in widgets folder (#31)

https://github.com/InfiniTimeOrg/InfiniTime/pull/1136 adds a new folder `widgets`
for source files.If it gets merged, this folder needs to be added to the build.

Add the source files to InfiniSim if the new folder exists

CMakeLists.txt

@@ -169,9 +169,14 @@ file(GLOB InfiniTime_FONTS
 file(GLOB InfiniTime_ICONS
   "${InfiniTime_DIR}/src/displayapp/icons/*.c"
 )
+file(GLOB InfiniTime_WIDGETS
+  "${InfiniTime_DIR}/src/displayapp/widgets/*.cpp"
+  "${InfiniTime_DIR}/src/displayapp/widgets/*.h"
+)
 target_sources(infinisim PUBLIC ${InfiniTime_SCREENS})
 target_sources(infinisim PUBLIC ${InfiniTime_FONTS})
 target_sources(infinisim PUBLIC ${InfiniTime_ICONS})
+target_sources(infinisim PUBLIC ${InfiniTime_WIDGETS})
 
 # add files directly from InfiniTime sources
 target_include_directories(infinisim PRIVATE "${InfiniTime_DIR}/src")