BaseTools: Convert Split tool to python

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3165

There are 2 reasons to convert Split tool from C to Python.
1. We are in the process of moving the Basetools Python code
to a separate repository. But there still are many C tools under
edk2/BaseTools. To make all Basetools be in the separate repo,
we can convert the C tools to Python tools.
2. The original Split tool is very slow. This python tool can reduce
90% time.

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

Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
Reviewed-by: Yuwei Chen <yuwei.chen@intel.com>

BaseTools/Source/Python/Split/__init__.py

@@ -0,0 +1,10 @@
+# @file
+#  Split a file into two pieces at the request offset.
+#
+#  Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+# Import Modules