Changelog:
===========
-During decoding, verify all pointers in arrays and tuples point to a valid location in the payload
-Fix memory leak warning in NodeVisitor and ABIRegistry
-Clear mypy misc-type errors and add top-level py.typed file back
Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
