Replace serialization/ and verif/ with MLPlatform's serialization_lib submodule

- Remove Usage and Format
- Run black on verif/*.py scripts

Signed-off-by: Kevin Cheng <kevin.cheng@arm.com>
Change-Id: Ie81515891eb0039540f614894f4b6b0e0e78ba74
diff --git a/.gitmodules b/.gitmodules
index 9a6276e..c112866 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,6 +1,6 @@
 [submodule "thirdparty/eigen"]
 	path = thirdparty/eigen
 	url = https://gitlab.com/libeigen/eigen.git
-[submodule "thirdparty/flatbuffers"]
-	path = thirdparty/flatbuffers
-	url = https://github.com/google/flatbuffers
+[submodule "thirdparty/serialization_lib"]
+	path = thirdparty/serialization_lib
+	url = https://review.mlplatform.org/tosa/serialization_lib