Change 1D attribute Tensors for scalar Tensors and use compound assignment...

Context

See aidge_core!273 (merged) related to aidge_core#207 (closed)

Change 1D attribute Tensors for scalar Tensors and use compound assignment operators on 'Parameter' to avoid reset of 'mGrad' attribute.

unit_tests/CMakeLists.txt

@@ -4,7 +4,7 @@ include(FetchContent)
 FetchContent_Declare(
   Catch2
   GIT_REPOSITORY https://github.com/catchorg/Catch2.git
-  GIT_TAG        v3.0.1 # or a later release
+  GIT_TAG        v3.7.1 # or a later release
 )
 FetchContent_MakeAvailable(Catch2)