Add a -Wweak-tables clang compiler flag, resolve all warnings, 2

[lnotspotl]

Due to the fact that python wheels are linking against a single shared library depthai-core and we're making extensive use of dynamic casting in our code base, it was necessary to remove all weak vtables from our codebase (some were ignored) to ensure proper casting. Specifically, on MacOS, dynamic_casts would rather confusingly return nullptr on objects with their parent class being that class being cast to.

This is a clang issue only and happens exclusively on MacOS.