BaseTools: replace string constants used for module types

replace raw strings in the code (note: except UPT) with constants.
SUP_MODULE_BASE was 'BASE'
SUP_MODULE_SEC was 'SEC'
SUP_MODULE_PEI_CORE was 'PEI_CORE'
SUP_MODULE_PEIM was 'PEIM'
SUP_MODULE_DXE_CORE was 'DXE_CORE'
SUP_MODULE_DXE_DRIVER was 'DXE_DRIVER'
SUP_MODULE_DXE_RUNTIME_DRIVER was 'DXE_RUNTIME_DRIVER'
SUP_MODULE_DXE_SAL_DRIVER was 'DXE_SAL_DRIVER'
SUP_MODULE_DXE_SMM_DRIVER was 'DXE_SMM_DRIVER'
SUP_MODULE_UEFI_DRIVER was 'UEFI_DRIVER'
SUP_MODULE_UEFI_APPLICATION was 'UEFI_APPLICATION'
SUP_MODULE_USER_DEFINED was 'USER_DEFINED'
SUP_MODULE_SMM_CORE was 'SMM_CORE'
SUP_MODULE_MM_STANDALONE was 'MM_STANDALONE'
SUP_MODULE_MM_CORE_STANDALONE was 'MM_CORE_STANDALONE'

Cc: Liming Gao <liming.gao@intel.com>
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jaben Carsey <jaben.carsey@intel.com>
Reviewed-by: Yonghong Zhu <yonghong.zhu@intel.com>