BaseTools: Extend the RAW format to support multiple binary files

BaseTools: Extend the RAW format to support multiple binary files

Current FDF spec updated to support multiple binary files for RAW File
in the [FV] and [Capsule] section. For the multiple normal files, it may
have the optional FfsAlignment.
Example:
FILE RAW = 197DB236-F856-4924-91F8-C1F12FB875F3 {
 Align=16 $(PLATFORM_PACKAGE)/Binaries/File1.pdb
 Align=16 $(PLATFORM_PACKAGE)/Binaries/File2.pdb
 Align=16 $(PLATFORM_PACKAGE)/Binaries/File3.pdb
}

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Yonghong Zhu <yonghong.zhu@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>