Game Menu: Handle CUSTOMCMD_ARGS with Windows paths using Backslashes

Fix CUSTOMCMD_ARGS with Windows paths using backslashes
getting mangled on save, from Yad stripping the '\' character.

We fix this by using `printf` in a subshell, which for
some reason allows Yad to read and thus save the path
correctly.

steamtinkerlaunch

@@ -7,7 +7,7 @@
 PREFIX="/usr"
 PROGNAME="SteamTinkerLaunch"
 NICEPROGNAME="Steam Tinker Launch"
-PROGVERS="v14.0.20240320-2"
+PROGVERS="v14.0.20240322-1 (customcmd-args-backslash-fix)"
 PROGCMD="${0##*/}"
 PROGINTERNALPROTNAME="Proton-stl"
 SHOSTL="stl"
@@ -5652,7 +5652,7 @@ function AllSettingsEntriesDummyFunction {
 --field="     $GUI_KEEPSTLOPEN!$DESC_KEEPSTLOPEN ('KEEPSTLOPEN')":CHK "${KEEPSTLOPEN/#-/ -}" `#CAT_Misc` `#SUB_Checkbox` `#MENU_GAME` \
 --field="     $GUI_USECUSTOMCMD!$DESC_USECUSTOMCMD ('USECUSTOMCMD')":CHK "${USECUSTOMCMD/#-/ -}" `#CAT_Misc` `#SUB_Checkbox` `#MENU_GAME` \
 --field="     $GUI_CUSTOMCMD!$DESC_CUSTOMCMD $GUI_ECHOPLAC ('CUSTOMCMD')":FL "${OPCUSTPATH/#-/ -}" `#CAT_Misc` `#MENU_GAME` \
---field="     $GUI_CUSTOMCMD_ARGS!$DESC_CUSTOMCMD_ARGS ('CUSTOMCMD_ARGS')" "${CUSTOMCMD_ARGS/#-/ -}" `#CAT_Misc` `#MENU_GAME` \
+--field="     $GUI_CUSTOMCMD_ARGS!$DESC_CUSTOMCMD_ARGS ('CUSTOMCMD_ARGS')" "$( printf "%s" "${CUSTOMCMD_ARGS/#-/ -}" )" `#CAT_Misc` `#MENU_GAME` \
 --field="     $GUI_FORK_CUSTOMCMD!$DESC_FORK_CUSTOMCMD ('FORK_CUSTOMCMD')":CHK "${FORK_CUSTOMCMD/#-/ -}" `#CAT_Misc` `#SUB_Checkbox` `#MENU_GAME` \
 --field="     $GUI_EXTPROGS_CUSTOMCMD!$DESC_EXTPROGS_CUSTOMCMD ('EXTPROGS_CUSTOMCMD')":CHK "${EXTPROGS_CUSTOMCMD/#-/ -}" `#CAT_Misc` `#SUB_Checkbox` `#MENU_GAME` \
 --field="     $GUI_ONLY_CUSTOMCMD!$DESC_ONLY_CUSTOMCMD ('ONLY_CUSTOMCMD')":CHK "${ONLY_CUSTOMCMD/#-/ -}" `#CAT_Misc` `#SUB_Checkbox` `#MENU_GAME` \