Adding the new SWC-137 weakness related to shadowed_memory_variables

[mojtaba-eshghie]

I added SWC-137 related to the shadowing of local variables of the function (memory variables) by the named return variables. This very probable weakness is also reported wrongly by the compiler as shadowed named return variable not the variable declared inside function which makes it even more misleading. https://github.com/mojtaba-eshghie/SWC-registry/commit/4d5defa2f995a40683e24a8eb6a1522474f87136