BaseTool/GenC: Fix build error when type is BASE or USER_DEFINED.

BaseTool/GenC: Fix build error when type is BASE or USER_DEFINED.

https://bugzilla.tianocore.org/show_bug.cgi?id=1544

1) The GenC tool does not include the constructor/destructor for
USER_DEFINED module. It should be included.
Only constructor/destructor with BASE type is included here.
The constructor/destructor with PEI/DXE/SMM type is still excluded
to keep original behavior.

2) The GenC tool includes the UnloadImage code for BASE module.
It should NOT be included.

3) The GenC tool uses EFI_STATUS and ASSERT_EFI_ERROR for BASE type.
It should use RETURN_STATUS and ASSERT_RETURN_ERROR.

4) The GenC tool miss DebugLib.h for BASE or USER_DEFINED module
AutoGen.c. Only Base.h is there. It should add Library/DebugLib.h.

Cc: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>