BaseTools: Add FMMT Python Tool

The FMMT python tool is used for firmware files operation, which has
the Fv/FFs-based 'View'&'Add'&'Delete'&'Replace' operation function:

1.Parse a FD(Firmware Device) / FV(Firmware Volume) / FFS(Firmware Files)
2.Add a new FFS into a FV file (both included in a FD file or not)
3.Replace an FFS in a FV file with a new FFS file
4.Delete an FFS in a FV file (both included in a FD file or not)
5.Extract the FFS from a FV file (both included in a FD file or not)

This version of FMMT Python tool does not support PEIM rebase feature,
this feature will be added in future update.

Currently the FMMT C tool is saved in edk2-staging repo, but its
quality and coding style can't meet the Edk2 quality, which is hard to
maintain (Hard/Duplicate Code; Regression bugs; Restrict usage).

The new Python version keeps same functions with origin C version. It
has higher quality and better coding style, and it is much easier to
extend new functions and to maintain.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1847
RFC Link: https://edk2.groups.io/g/devel/message/82877
Staging Link: https://github.com/tianocore/edk2-staging/tree/PyFMMT

Cc: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Signed-off-by: Yuwei Chen <yuwei.chen@intel.com>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>
Acked-by: Liming Gao <gaoliming@byosoft.com.cn>

BaseTools/Source/Python/FirmwareStorageFormat/FfsFileHeader.py

@@ -0,0 +1,66 @@
+## @file
+# This file is used to define the Ffs Header C Struct.
+#
+# Copyright (c) 2021-, Intel Corporation. All rights reserved.<BR>
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+from struct import *
+from ctypes import *
+from FirmwareStorageFormat.Common import *
+
+EFI_FFS_FILE_HEADER_LEN = 24
+EFI_FFS_FILE_HEADER2_LEN = 32
+
+class CHECK_SUM(Structure):
+    _pack_ = 1
+    _fields_ = [
+        ('Header',                   c_uint8),
+        ('File',                     c_uint8),
+    ]
+
+class EFI_FFS_INTEGRITY_CHECK(Union):
+    _pack_ = 1
+    _fields_ = [
+        ('Checksum',                 CHECK_SUM),
+        ('Checksum16',               c_uint16),
+    ]
+
+
+class EFI_FFS_FILE_HEADER(Structure):
+    _pack_ = 1
+    _fields_ = [
+        ('Name',                     GUID),
+        ('IntegrityCheck',           EFI_FFS_INTEGRITY_CHECK),
+        ('Type',                     c_uint8),
+        ('Attributes',               c_uint8),
+        ('Size',                     ARRAY(c_uint8, 3)),
+        ('State',                    c_uint8),
+    ]
+
+    @property
+    def FFS_FILE_SIZE(self) -> int:
+        return self.Size[0] | self.Size[1] << 8 | self.Size[2] << 16
+
+    @property
+    def HeaderLength(self) -> int:
+        return 24
+
+class EFI_FFS_FILE_HEADER2(Structure):
+    _pack_ = 1
+    _fields_ = [
+        ('Name',                     GUID),
+        ('IntegrityCheck',           EFI_FFS_INTEGRITY_CHECK),
+        ('Type',                     c_uint8),
+        ('Attributes',               c_uint8),
+        ('Size',                     ARRAY(c_uint8, 3)),
+        ('State',                    c_uint8),
+        ('ExtendedSize',             c_uint64),
+    ]
+
+    @property
+    def FFS_FILE_SIZE(self) -> int:
+        return self.ExtendedSize
+
+    @property
+    def HeaderLength(self) -> int:
+        return 32